From c415283fcb6ff8c454549586f89c094a9a69988d Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 26 Aug 2024 14:57:07 +0200
Subject: [PATCH 1/9] Add 'check' commands, a variation of assert command

---
 Source/Core/AST/AbsyCmd.cs                    |  10 +-
 Source/Core/BoogiePL.atg                      |   4 +
 Source/Core/Parser.cs                         | 550 +++++++++---------
 Source/Core/Scanner.cs                        | 135 ++---
 Source/VCGeneration/CommandTransformations.cs |  13 +-
 Source/VCGeneration/FocusAttribute.cs         |   2 +-
 Source/VCGeneration/ManualSplitFinder.cs      |  15 +-
 .../VerificationConditionGenerator.cs         |   4 -
 Test/test0/Split/Foo.split.1.bpl.expect       |   2 +-
 Test/test0/Split/Foo.split.2.bpl.expect       |   2 +-
 Test/test0/Split/Foo.split.3.bpl.expect       |   2 -
 Test/test0/Split/Split.bpl                    |   4 +-
 12 files changed, 384 insertions(+), 359 deletions(-)

diff --git a/Source/Core/AST/AbsyCmd.cs b/Source/Core/AST/AbsyCmd.cs
index 3583e68b5..5d55ff98a 100644
--- a/Source/Core/AST/AbsyCmd.cs
+++ b/Source/Core/AST/AbsyCmd.cs
@@ -2995,8 +2995,12 @@ public EEDTemplate(string reason, List<Expr /*!*/> /*!*/ exprList)
     }
   }
 
-  public class AssertCmd : PredicateCmd
-  {
+  public class AssertCmd : PredicateCmd {
+    /// <summary>
+    /// Whether to remember the asserted fact, after it has been asserted
+    /// Particularly relevant when doing splits
+    /// </summary>
+    public bool Remember { get; set; } = true;
     public Expr OrigExpr;
     public Dictionary<Variable, Expr> IncarnationMap;
 
@@ -3048,7 +3052,7 @@ public AssertCmd(IToken tok, Expr expr, QKeyValue kv = null)
 
     public override void Emit(TokenTextWriter stream, int level)
     {
-      stream.Write(this, level, "assert ");
+      stream.Write(this, level, Remember ? "assert " : "check ");
       EmitAttributes(stream, Attributes);
       this.Expr.Emit(stream);
       stream.WriteLine(";");
diff --git a/Source/Core/BoogiePL.atg b/Source/Core/BoogiePL.atg
index 66c5789aa..956787fc5 100644
--- a/Source/Core/BoogiePL.atg
+++ b/Source/Core/BoogiePL.atg
@@ -1149,6 +1149,10 @@ LabelOrCmd<out Cmd c, out IToken label>
     { Attribute<ref kv> }
     Proposition<out e>    (. c = new AssertCmd(x, e, kv); .)
     ";"
+  | "check"              (. x = t; .)
+      { Attribute<ref kv> }
+      Proposition<out e>    (. c = new AssertCmd(x, e, kv) { Remember = false }; .)
+      ";"
   | "assume"              (. x = t; .)
     { Attribute<ref kv> }
     Proposition<out e>    (. c = new AssumeCmd(x, e, kv); .)
diff --git a/Source/Core/Parser.cs b/Source/Core/Parser.cs
index 0094b0fc3..f7e4d9dc2 100644
--- a/Source/Core/Parser.cs
+++ b/Source/Core/Parser.cs
@@ -36,7 +36,7 @@ public class Parser {
 	public const int _decimal = 5;
 	public const int _dec_float = 6;
 	public const int _float = 7;
-	public const int maxT = 124;
+	public const int maxT = 125;
 
 	const bool _T = true;
 	const bool _x = false;
@@ -304,7 +304,7 @@ void BoogiePL() {
 					 Pgm.AddTopLevelDeclaration(im);
 					}
 					
-				} else SynErr(125);
+				} else SynErr(126);
 				break;
 			}
 			case 36: case 37: case 38: case 42: case 43: case 44: case 45: case 46: {
@@ -328,7 +328,7 @@ void BoogiePL() {
 					}
 					isPure = false;
 					
-				} else SynErr(126);
+				} else SynErr(127);
 				break;
 			}
 			case 51: {
@@ -367,7 +367,7 @@ void Consts(out List<Declaration>/*!*/ ds) {
 				axioms.Add(axiom); ds.Add(axiom); 
 			}
 			Expect(27);
-		} else SynErr(127);
+		} else SynErr(128);
 		foreach(TypedIdent/*!*/ x in xs){
 		 Contract.Assert(x != null);
 		 var constant = new Constant(y, x, u, kv, axioms);
@@ -421,7 +421,7 @@ void Function(out List<Declaration>/*!*/ ds) {
 			Get();
 			Type(out retTy);
 			retTyd = new TypedIdent(retTy.tok, TypedIdent.NoName, retTy); 
-		} else SynErr(128);
+		} else SynErr(129);
 		if (la.kind == 26) {
 			Get();
 			Expression(out tmp);
@@ -446,7 +446,7 @@ void Function(out List<Declaration>/*!*/ ds) {
 			Expect(27);
 		} else if (la.kind == 10) {
 			Get();
-		} else SynErr(129);
+		} else SynErr(130);
 		if (retTyd == null) {
 		 // construct a dummy type for the case of syntax error
 		 retTyd = new TypedIdent(t, TypedIdent.NoName, new BasicType(t, SimpleType.Int));
@@ -632,7 +632,7 @@ void YieldProcedureDecl(out YieldProcedureDecl ypDecl, out Implementation impl)
 			impl = new Implementation(name, name.val, new List<TypeVariable>(), Formal.StripWhereClauses(ins), Formal.StripWhereClauses(outs),
 			                         locals, stmtList, kv == null ? null : (QKeyValue)kv.Clone(), this.errors);
 			
-		} else SynErr(130);
+		} else SynErr(131);
 		ypDecl = new YieldProcedureDecl(name, name.val, moverType, ins, outs, pre, mods, post, yieldRequires, yieldEnsures, yieldPreserves, refinedAction, kv); 
 	}
 
@@ -670,7 +670,7 @@ void Procedure(bool isPure, out Procedure/*!*/ proc, out /*maybe null*/ Implemen
 			impl = new Implementation(x, x.val, typeParams.ConvertAll(tp => new TypeVariable(tp.tok, tp.Name)),
 			                         Formal.StripWhereClauses(ins), Formal.StripWhereClauses(outs), locals, stmtList, kv == null ? null : (QKeyValue)kv.Clone(), this.errors);
 			
-		} else SynErr(131);
+		} else SynErr(132);
 		proc = new Procedure(x, x.val, typeParams, ins, outs, isPure, pre, mods, post, kv); 
 	}
 
@@ -722,7 +722,7 @@ void ActionDecl(bool isPure, out ActionDecl actionDecl, out Implementation impl,
 			impl = new Implementation(name, name.val, new List<TypeVariable>(), Formal.StripWhereClauses(ins), Formal.StripWhereClauses(outs),
 			                              locals, stmtList, kv == null ? null : (QKeyValue)kv.Clone(), this.errors);
 			
-		} else SynErr(132);
+		} else SynErr(133);
 		if (isPure) {
 		 if (moverType == MoverType.None)
 		 {
@@ -860,7 +860,7 @@ void Type(out Bpl.Type/*!*/ ty) {
 			ty = new UnresolvedTypeIdentifier (tok, tok.val, args); 
 		} else if (la.kind == 19 || la.kind == 21) {
 			MapType(out ty);
-		} else SynErr(133);
+		} else SynErr(134);
 	}
 
 	void AttributesIdsTypeWhere(bool allowWhereClauses, string context, System.Action<TypedIdent, QKeyValue> action ) {
@@ -896,7 +896,7 @@ void IdsTypeWhere(bool allowWhereClauses, string context, System.Action<TypedIde
 	void Expression(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; 
 		ImpliesExpression(false, out e0);
-		while (la.kind == 73 || la.kind == 74) {
+		while (la.kind == 74 || la.kind == 75) {
 			EquivOp();
 			x = t; 
 			ImpliesExpression(false, out e1);
@@ -919,7 +919,7 @@ void TypeAtom(out Bpl.Type/*!*/ ty) {
 			Get();
 			Type(out ty);
 			Expect(12);
-		} else SynErr(134);
+		} else SynErr(135);
 	}
 
 	void Ident(out IToken/*!*/ x) {
@@ -969,7 +969,7 @@ void Ident(out IToken/*!*/ x) {
 			t.kind = _ident; 
 			break;
 		}
-		default: SynErr(135); break;
+		default: SynErr(136); break;
 		}
 		x = t;
 		if (x.val.StartsWith("\\"))
@@ -995,7 +995,7 @@ void TypeArgs(List<Bpl.Type>/*!*/ ts) {
 		} else if (la.kind == 19 || la.kind == 21) {
 			MapType(out ty);
 			ts.Add(ty); 
-		} else SynErr(136);
+		} else SynErr(137);
 	}
 
 	void MapType(out Bpl.Type/*!*/ ty) {
@@ -1156,7 +1156,7 @@ void MoverQualifier(ref MoverType moverType) {
 		} else if (la.kind == 45) {
 			Get();
 			moverType = MoverType.Atomic; 
-		} else SynErr(137);
+		} else SynErr(138);
 	}
 
 	void SpecAction(ref ActionDeclRef refinedAction, ref ActionDeclRef invariantAction, List<IdentifierExpr> mods, List<ActionDeclRef> creates, List<Requires> requires, List<CallCmd> yieldRequires, List<AssertCmd> asserts) {
@@ -1177,7 +1177,7 @@ void SpecAction(ref ActionDeclRef refinedAction, ref ActionDeclRef invariantActi
 			SpecYieldRequires(requires, yieldRequires);
 		} else if (la.kind == 47) {
 			SpecAsserts(asserts);
-		} else SynErr(138);
+		} else SynErr(139);
 	}
 
 	void ImplBody(out List<Variable>/*!*/ locals, out StmtList/*!*/ stmtList) {
@@ -1232,10 +1232,10 @@ void SpecYieldRequires(List<Requires> pre, List<CallCmd> yieldRequires ) {
 			}
 			Proposition(out e);
 			pre.Add(new Requires(tok, false, e, null, kv)); 
-		} else if (la.kind == 37 || la.kind == 52 || la.kind == 70) {
+		} else if (la.kind == 37 || la.kind == 52 || la.kind == 71) {
 			CallCmd(out cmd);
 			yieldRequires.Add((CallCmd)cmd); 
-		} else SynErr(139);
+		} else SynErr(140);
 		Expect(10);
 	}
 
@@ -1263,7 +1263,7 @@ void SpecYieldPrePost(ref ActionDeclRef refinedAction, List<Requires> pre, List<
 			SpecYieldPreserves(yieldPreserves);
 		} else if (la.kind == 53) {
 			SpecModifies(mods);
-		} else SynErr(140);
+		} else SynErr(141);
 	}
 
 	void CallCmd(out Cmd c) {
@@ -1281,7 +1281,7 @@ void CallCmd(out Cmd c) {
 			Get();
 			isFree = true; 
 		}
-		Expect(70);
+		Expect(71);
 		x = t; 
 		CallParams(isAsync, isFree, x, out c);
 		
@@ -1297,10 +1297,10 @@ void SpecYieldEnsures(List<Ensures> post, List<CallCmd> yieldEnsures ) {
 			}
 			Proposition(out e);
 			post.Add(new Ensures(tok, false, e, null, kv)); 
-		} else if (la.kind == 37 || la.kind == 52 || la.kind == 70) {
+		} else if (la.kind == 37 || la.kind == 52 || la.kind == 71) {
 			CallCmd(out cmd);
 			yieldEnsures.Add((CallCmd)cmd); 
-		} else SynErr(141);
+		} else SynErr(142);
 		Expect(10);
 	}
 
@@ -1340,7 +1340,7 @@ void Spec(List<Requires> pre, List<IdentifierExpr> mods, List<Ensures> post) {
 			SpecPrePost(true, pre, post);
 		} else if (la.kind == 48 || la.kind == 49) {
 			SpecPrePost(false, pre, post);
-		} else SynErr(142);
+		} else SynErr(143);
 	}
 
 	void SpecPrePost(bool free, List<Requires>/*!*/ pre, List<Ensures>/*!*/ post) {
@@ -1363,7 +1363,7 @@ void SpecPrePost(bool free, List<Requires>/*!*/ pre, List<Ensures>/*!*/ post) {
 			Proposition(out e);
 			Expect(10);
 			post.Add(new Ensures(tok, free, e, null, kv)); 
-		} else SynErr(143);
+		} else SynErr(144);
 	}
 
 	void StmtList(out StmtList/*!*/ stmtList) {
@@ -1457,7 +1457,7 @@ void LabelOrCmd(out Cmd c, out IToken label) {
 				hideRevealId = new IdentifierExpr(t, t.val); 
 			} else if (la.kind == 59) {
 				Get();
-			} else SynErr(144);
+			} else SynErr(145);
 			c = hideRevealId == null ? new HideRevealCmd(t, mode) : new HideRevealCmd(hideRevealId, mode); 
 			Expect(10);
 		} else if (la.kind == 63) {
@@ -1486,9 +1486,18 @@ void LabelOrCmd(out Cmd c, out IToken label) {
 				Attribute(ref kv);
 			}
 			Proposition(out e);
-			c = new AssumeCmd(x, e, kv); 
+			c = new AssertCmd(x, e, kv) { Remember = false }; 
 			Expect(10);
 		} else if (la.kind == 67) {
+			Get();
+			x = t; 
+			while (la.kind == 26) {
+				Attribute(ref kv);
+			}
+			Proposition(out e);
+			c = new AssumeCmd(x, e, kv); 
+			Expect(10);
+		} else if (la.kind == 68) {
 			Get();
 			x = t; 
 			Idents(out xs);
@@ -1500,14 +1509,14 @@ void LabelOrCmd(out Cmd c, out IToken label) {
 			}
 			c = new HavocCmd(x,ids);
 			
-		} else if (la.kind == 37 || la.kind == 52 || la.kind == 70) {
+		} else if (la.kind == 37 || la.kind == 52 || la.kind == 71) {
 			CallCmd(out cn);
 			Expect(10);
 			c = cn; 
-		} else if (la.kind == 71) {
+		} else if (la.kind == 72) {
 			ParCallCmd(out cn);
 			c = cn; 
-		} else SynErr(145);
+		} else SynErr(146);
 	}
 
 	void StructuredCmd(out StructuredCmd/*!*/ ec) {
@@ -1523,7 +1532,7 @@ void StructuredCmd(out StructuredCmd/*!*/ ec) {
 		} else if (la.kind == 60) {
 			BreakCmd(out bcmd);
 			ec = bcmd; 
-		} else SynErr(146);
+		} else SynErr(147);
 	}
 
 	void TransferCmd(out TransferCmd/*!*/ tc) {
@@ -1543,7 +1552,7 @@ void TransferCmd(out TransferCmd/*!*/ tc) {
 		} else if (la.kind == 55) {
 			Get();
 			tc = new ReturnCmd(t); 
-		} else SynErr(147);
+		} else SynErr(148);
 		Expect(10);
 	}
 
@@ -1568,7 +1577,7 @@ void IfCmd(out IfCmd/*!*/ ifcmd) {
 				Get();
 				StmtList(out els);
 				elseOption = els; 
-			} else SynErr(148);
+			} else SynErr(149);
 		}
 		ifcmd = new IfCmd(x, guard, thn, elseIfOption, elseOption); 
 	}
@@ -1604,10 +1613,10 @@ void WhileCmd(out WhileCmd wcmd) {
 				}
 				kv = null;
 				
-			} else if (la.kind == 37 || la.kind == 52 || la.kind == 70) {
+			} else if (la.kind == 37 || la.kind == 52 || la.kind == 71) {
 				CallCmd(out cmd);
 				yields.Add((CallCmd)cmd); 
-			} else SynErr(149);
+			} else SynErr(150);
 			Expect(10);
 		}
 		Expect(26);
@@ -1638,7 +1647,7 @@ void Guard(out Expr e) {
 		} else if (StartOf(19)) {
 			Expression(out ee);
 			e = ee; 
-		} else SynErr(150);
+		} else SynErr(151);
 		Expect(12);
 	}
 
@@ -1664,7 +1673,7 @@ void LabelOrAssign(out Cmd c, out IToken label) {
 			Expect(12);
 			lhsExpr = new NAryExpr(x, new FunctionCall(new IdentifierExpr(id, id.val)), ids.Select(id => new IdentifierExpr(id, id.val)).ToList<Expr>());
 			
-			Expect(68);
+			Expect(69);
 			x = t; /* use location of := */ 
 			while (la.kind == 26) {
 				Attribute(ref kv);
@@ -1676,7 +1685,7 @@ void LabelOrAssign(out Cmd c, out IToken label) {
 		} else if (StartOf(20)) {
 			lhss = new List<AssignLhs/*!*/>(); 
 			lhs = new SimpleAssignLhs(id, new IdentifierExpr(id, id.val)); 
-			while (la.kind == 19 || la.kind == 69) {
+			while (la.kind == 19 || la.kind == 70) {
 				if (la.kind == 19) {
 					MapAssignIndex(out y, out indexes);
 					lhs = new MapAssignLhs(y, lhs, indexes); 
@@ -1690,7 +1699,7 @@ void LabelOrAssign(out Cmd c, out IToken label) {
 				Get();
 				Ident(out id);
 				lhs = new SimpleAssignLhs(id, new IdentifierExpr(id, id.val)); 
-				while (la.kind == 19 || la.kind == 69) {
+				while (la.kind == 19 || la.kind == 70) {
 					if (la.kind == 19) {
 						MapAssignIndex(out y, out indexes);
 						lhs = new MapAssignLhs(y, lhs, indexes); 
@@ -1701,7 +1710,7 @@ void LabelOrAssign(out Cmd c, out IToken label) {
 				}
 				lhss.Add(lhs); 
 			}
-			Expect(68);
+			Expect(69);
 			x = t; /* use location of := */ 
 			while (la.kind == 26) {
 				Attribute(ref kv);
@@ -1716,7 +1725,7 @@ void LabelOrAssign(out Cmd c, out IToken label) {
 			}
 			Expect(10);
 			c = new AssignCmd(x, lhss, rhss, kv); 
-		} else SynErr(151);
+		} else SynErr(152);
 	}
 
 	void ParCallCmd(out Cmd d) {
@@ -1725,11 +1734,11 @@ void ParCallCmd(out Cmd d) {
 		Cmd c = null;
 		List<CallCmd> callCmds = new List<CallCmd>();
 		
-		Expect(71);
+		Expect(72);
 		x = t; 
 		CallParams(false, false, x, out c);
 		callCmds.Add((CallCmd)c); 
-		while (la.kind == 72) {
+		while (la.kind == 73) {
 			Get();
 			CallParams(false, false, x, out c);
 			callCmds.Add((CallCmd)c); 
@@ -1758,7 +1767,7 @@ void MapAssignIndex(out IToken/*!*/ x, out List<Expr/*!*/>/*!*/ indexes) {
 
 	void FieldAccess(out IToken x, out FieldAccess fieldAccess) {
 		Contract.Ensures(Contract.ValueAtReturn(out fieldAccess) != null); IToken id; 
-		Expect(69);
+		Expect(70);
 		x = t; 
 		Ident(out id);
 		fieldAccess = new FieldAccess(id, id.val); 
@@ -1790,7 +1799,7 @@ void CallParams(bool isAsync, bool isFree, IToken x, out Cmd c) {
 			}
 			Expect(12);
 			c = new CallCmd(x, first.val, es, ids, kv); ((CallCmd) c).IsFree = isFree; ((CallCmd) c).IsAsync = isAsync; 
-		} else if (la.kind == 14 || la.kind == 68) {
+		} else if (la.kind == 14 || la.kind == 69) {
 			ids.Add(new IdentifierExpr(first, first.val)); 
 			if (la.kind == 14) {
 				Get();
@@ -1802,7 +1811,7 @@ void CallParams(bool isAsync, bool isFree, IToken x, out Cmd c) {
 					ids.Add(new IdentifierExpr(p, p.val)); 
 				}
 			}
-			Expect(68);
+			Expect(69);
 			Ident(out first);
 			Expect(11);
 			if (StartOf(19)) {
@@ -1816,7 +1825,7 @@ void CallParams(bool isAsync, bool isFree, IToken x, out Cmd c) {
 			}
 			Expect(12);
 			c = new CallCmd(x, first.val, es, ids, kv); ((CallCmd) c).IsFree = isFree; ((CallCmd) c).IsAsync = isAsync; 
-		} else SynErr(152);
+		} else SynErr(153);
 	}
 
 	void Expressions(out List<Expr>/*!*/ es) {
@@ -1834,7 +1843,7 @@ void ImpliesExpression(bool noExplies, out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; 
 		LogicalExpression(out e0);
 		if (StartOf(21)) {
-			if (la.kind == 75 || la.kind == 76) {
+			if (la.kind == 76 || la.kind == 77) {
 				ImpliesOp();
 				x = t; 
 				ImpliesExpression(true, out e1);
@@ -1846,7 +1855,7 @@ void ImpliesExpression(bool noExplies, out Expr/*!*/ e0) {
 				x = t; 
 				LogicalExpression(out e1);
 				e0 = Expr.Binary(x, BinaryOperator.Opcode.Imp, e1, e0); 
-				while (la.kind == 77 || la.kind == 78) {
+				while (la.kind == 78 || la.kind == 79) {
 					ExpliesOp();
 					x = t; 
 					LogicalExpression(out e1);
@@ -1857,23 +1866,23 @@ void ImpliesExpression(bool noExplies, out Expr/*!*/ e0) {
 	}
 
 	void EquivOp() {
-		if (la.kind == 73) {
+		if (la.kind == 74) {
 			Get();
-		} else if (la.kind == 74) {
+		} else if (la.kind == 75) {
 			Get();
-		} else SynErr(153);
+		} else SynErr(154);
 	}
 
 	void LogicalExpression(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; 
 		RelationalExpression(out e0);
 		if (StartOf(22)) {
-			if (la.kind == 79 || la.kind == 80) {
+			if (la.kind == 80 || la.kind == 81) {
 				AndOp();
 				x = t; 
 				RelationalExpression(out e1);
 				e0 = Expr.Binary(x, BinaryOperator.Opcode.And, e0, e1); 
-				while (la.kind == 79 || la.kind == 80) {
+				while (la.kind == 80 || la.kind == 81) {
 					AndOp();
 					x = t; 
 					RelationalExpression(out e1);
@@ -1884,7 +1893,7 @@ void LogicalExpression(out Expr/*!*/ e0) {
 				x = t; 
 				RelationalExpression(out e1);
 				e0 = Expr.Binary(x, BinaryOperator.Opcode.Or, e0, e1); 
-				while (la.kind == 81 || la.kind == 82) {
+				while (la.kind == 82 || la.kind == 83) {
 					OrOp();
 					x = t; 
 					RelationalExpression(out e1);
@@ -1895,19 +1904,19 @@ void LogicalExpression(out Expr/*!*/ e0) {
 	}
 
 	void ImpliesOp() {
-		if (la.kind == 75) {
+		if (la.kind == 76) {
 			Get();
-		} else if (la.kind == 76) {
+		} else if (la.kind == 77) {
 			Get();
-		} else SynErr(154);
+		} else SynErr(155);
 	}
 
 	void ExpliesOp() {
-		if (la.kind == 77) {
+		if (la.kind == 78) {
 			Get();
-		} else if (la.kind == 78) {
+		} else if (la.kind == 79) {
 			Get();
-		} else SynErr(155);
+		} else SynErr(156);
 	}
 
 	void RelationalExpression(out Expr/*!*/ e0) {
@@ -1921,25 +1930,25 @@ void RelationalExpression(out Expr/*!*/ e0) {
 	}
 
 	void AndOp() {
-		if (la.kind == 79) {
+		if (la.kind == 80) {
 			Get();
-		} else if (la.kind == 80) {
+		} else if (la.kind == 81) {
 			Get();
-		} else SynErr(156);
+		} else SynErr(157);
 	}
 
 	void OrOp() {
-		if (la.kind == 81) {
+		if (la.kind == 82) {
 			Get();
-		} else if (la.kind == 82) {
+		} else if (la.kind == 83) {
 			Get();
-		} else SynErr(157);
+		} else SynErr(158);
 	}
 
 	void BvTerm(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; 
 		Term(out e0);
-		while (la.kind == 90) {
+		while (la.kind == 91) {
 			Get();
 			x = t; 
 			Term(out e1);
@@ -1950,7 +1959,7 @@ void BvTerm(out Expr/*!*/ e0) {
 	void RelOp(out IToken/*!*/ x, out BinaryOperator.Opcode op) {
 		Contract.Ensures(Contract.ValueAtReturn(out x) != null); x = Token.NoToken; op=BinaryOperator.Opcode.Add/*(dummy)*/; 
 		switch (la.kind) {
-		case 83: {
+		case 84: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Eq; 
 			break;
@@ -1965,44 +1974,44 @@ void RelOp(out IToken/*!*/ x, out BinaryOperator.Opcode op) {
 			x = t; op=BinaryOperator.Opcode.Gt; 
 			break;
 		}
-		case 84: {
+		case 85: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Le; 
 			break;
 		}
-		case 85: {
+		case 86: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Ge; 
 			break;
 		}
-		case 86: {
+		case 87: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Neq; 
 			break;
 		}
-		case 87: {
+		case 88: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Neq; 
 			break;
 		}
-		case 88: {
+		case 89: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Le; 
 			break;
 		}
-		case 89: {
+		case 90: {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Ge; 
 			break;
 		}
-		default: SynErr(158); break;
+		default: SynErr(159); break;
 		}
 	}
 
 	void Term(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; BinaryOperator.Opcode op; 
 		Factor(out e0);
-		while (la.kind == 91 || la.kind == 92) {
+		while (la.kind == 92 || la.kind == 93) {
 			AddOp(out x, out op);
 			Factor(out e1);
 			e0 = Expr.Binary(x, op, e0, e1); 
@@ -2021,19 +2030,19 @@ void Factor(out Expr/*!*/ e0) {
 
 	void AddOp(out IToken/*!*/ x, out BinaryOperator.Opcode op) {
 		Contract.Ensures(Contract.ValueAtReturn(out x) != null); x = Token.NoToken; op=BinaryOperator.Opcode.Add/*(dummy)*/; 
-		if (la.kind == 91) {
+		if (la.kind == 92) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Add; 
-		} else if (la.kind == 92) {
+		} else if (la.kind == 93) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Sub; 
-		} else SynErr(159);
+		} else SynErr(160);
 	}
 
 	void Power(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expr/*!*/ e1; 
 		IsConstructor(out e0);
-		if (la.kind == 96) {
+		if (la.kind == 97) {
 			Get();
 			x = t; 
 			Power(out e1);
@@ -2046,22 +2055,22 @@ void MulOp(out IToken/*!*/ x, out BinaryOperator.Opcode op) {
 		if (la.kind == 59) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Mul; 
-		} else if (la.kind == 93) {
+		} else if (la.kind == 94) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Div; 
-		} else if (la.kind == 94) {
+		} else if (la.kind == 95) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.Mod; 
-		} else if (la.kind == 95) {
+		} else if (la.kind == 96) {
 			Get();
 			x = t; op=BinaryOperator.Opcode.RealDiv; 
-		} else SynErr(160);
+		} else SynErr(161);
 	}
 
 	void IsConstructor(out Expr/*!*/ e0) {
 		Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x, id; 
 		UnaryExpression(out e0);
-		if (la.kind == 97) {
+		if (la.kind == 98) {
 			Get();
 			x = t; 
 			Ident(out id);
@@ -2075,27 +2084,27 @@ void UnaryExpression(out Expr/*!*/ e) {
 		Contract.Ensures(Contract.ValueAtReturn(out e) != null); IToken/*!*/ x;
 		e = dummyExpr;
 		
-		if (la.kind == 92) {
+		if (la.kind == 93) {
 			Get();
 			x = t; 
 			UnaryExpression(out e);
 			e = Expr.Unary(x, UnaryOperator.Opcode.Neg, e); 
-		} else if (la.kind == 98 || la.kind == 99) {
+		} else if (la.kind == 99 || la.kind == 100) {
 			NegOp();
 			x = t; 
 			UnaryExpression(out e);
 			e = Expr.Unary(x, UnaryOperator.Opcode.Not, e); 
 		} else if (StartOf(25)) {
 			CoercionExpression(out e);
-		} else SynErr(161);
+		} else SynErr(162);
 	}
 
 	void NegOp() {
-		if (la.kind == 98) {
+		if (la.kind == 99) {
 			Get();
-		} else if (la.kind == 99) {
+		} else if (la.kind == 100) {
 			Get();
-		} else SynErr(162);
+		} else SynErr(163);
 	}
 
 	void CoercionExpression(out Expr/*!*/ e) {
@@ -2119,7 +2128,7 @@ void CoercionExpression(out Expr/*!*/ e) {
 				 e = new BvBounds(x, bn, ((LiteralExpr)e).asBigNum);
 				}
 				
-			} else SynErr(163);
+			} else SynErr(164);
 		}
 	}
 
@@ -2131,7 +2140,7 @@ void ArrayExpression(out Expr/*!*/ e) {
 		List<Expr>/*!*/ allArgs = dummyExprSeq;
 		
 		AtomExpression(out e);
-		while (la.kind == 19 || la.kind == 69) {
+		while (la.kind == 19 || la.kind == 70) {
 			if (la.kind == 19) {
 				Get();
 				x = t; allArgs = new List<Expr> ();
@@ -2153,7 +2162,7 @@ void ArrayExpression(out Expr/*!*/ e) {
 							allArgs.Add(e1);
 							
 						}
-						if (la.kind == 68) {
+						if (la.kind == 69) {
 							Get();
 							Expression(out e1);
 							if (bvExtract || e1 is BvBounds)
@@ -2186,12 +2195,12 @@ void ArrayExpression(out Expr/*!*/ e) {
 				} else if (la.kind == 11) {
 					Get();
 					Ident(out id);
-					Expect(68);
+					Expect(69);
 					x = t; 
 					Expression(out e1);
 					Expect(12);
 					e = new NAryExpr(x, new FieldUpdate(id, id.val), new List<Expr> { e, e1 }); 
-				} else SynErr(164);
+				} else SynErr(165);
 			}
 		}
 	}
@@ -2218,18 +2227,18 @@ void AtomExpression(out Expr/*!*/ e) {
 		List<Block/*!*/>/*!*/ blocks;
 		
 		switch (la.kind) {
-		case 100: {
+		case 101: {
 			Get();
 			e = new LiteralExpr(t, false); 
 			break;
 		}
-		case 101: {
+		case 102: {
 			Get();
 			e = new LiteralExpr(t, true); 
 			break;
 		}
-		case 102: case 103: {
-			if (la.kind == 102) {
+		case 103: case 104: {
+			if (la.kind == 103) {
 				Get();
 			} else {
 				Get();
@@ -2237,8 +2246,8 @@ void AtomExpression(out Expr/*!*/ e) {
 			e = new LiteralExpr(t, RoundingMode.RNE); 
 			break;
 		}
-		case 104: case 105: {
-			if (la.kind == 104) {
+		case 105: case 106: {
+			if (la.kind == 105) {
 				Get();
 			} else {
 				Get();
@@ -2246,8 +2255,8 @@ void AtomExpression(out Expr/*!*/ e) {
 			e = new LiteralExpr(t, RoundingMode.RNA); 
 			break;
 		}
-		case 106: case 107: {
-			if (la.kind == 106) {
+		case 107: case 108: {
+			if (la.kind == 107) {
 				Get();
 			} else {
 				Get();
@@ -2255,8 +2264,8 @@ void AtomExpression(out Expr/*!*/ e) {
 			e = new LiteralExpr(t, RoundingMode.RTP); 
 			break;
 		}
-		case 108: case 109: {
-			if (la.kind == 108) {
+		case 109: case 110: {
+			if (la.kind == 109) {
 				Get();
 			} else {
 				Get();
@@ -2264,8 +2273,8 @@ void AtomExpression(out Expr/*!*/ e) {
 			e = new LiteralExpr(t, RoundingMode.RTN); 
 			break;
 		}
-		case 110: case 111: {
-			if (la.kind == 110) {
+		case 111: case 112: {
+			if (la.kind == 111) {
 				Get();
 			} else {
 				Get();
@@ -2308,12 +2317,12 @@ void AtomExpression(out Expr/*!*/ e) {
 					e = new NAryExpr(x, new FunctionCall(id), es); 
 				} else if (la.kind == 12) {
 					e = new NAryExpr(x, new FunctionCall(id), new List<Expr>()); 
-				} else SynErr(165);
+				} else SynErr(166);
 				Expect(12);
 			}
 			break;
 		}
-		case 112: {
+		case 113: {
 			Get();
 			x = t; 
 			Expect(11);
@@ -2346,19 +2355,19 @@ void AtomExpression(out Expr/*!*/ e) {
 				Expression(out e);
 				if (e is BvBounds)
 				 this.SemErr("parentheses around bitvector bounds are not allowed"); 
-			} else if (la.kind == 116 || la.kind == 117) {
+			} else if (la.kind == 117 || la.kind == 118) {
 				Forall();
 				x = t; 
 				QuantifierBody(x, out typeParams, out ds, out kv, out trig, out e);
 				if (typeParams.Count + ds.Count > 0)
 				 e = new ForallExpr(x, typeParams, ds, kv, trig, e); 
-			} else if (la.kind == 118 || la.kind == 119) {
+			} else if (la.kind == 119 || la.kind == 120) {
 				Exists();
 				x = t; 
 				QuantifierBody(x, out typeParams, out ds, out kv, out trig, out e);
 				if (typeParams.Count + ds.Count > 0)
 				 e = new ExistsExpr(x, typeParams, ds, kv, trig, e); 
-			} else if (la.kind == 120 || la.kind == 121) {
+			} else if (la.kind == 121 || la.kind == 122) {
 				Lambda();
 				x = t; 
 				QuantifierBody(x, out typeParams, out ds, out kv, out trig, out e);
@@ -2368,7 +2377,7 @@ void AtomExpression(out Expr/*!*/ e) {
 				 e = new LambdaExpr(x, typeParams, ds, kv, e); 
 			} else if (la.kind == 9) {
 				LetExpr(out e);
-			} else SynErr(166);
+			} else SynErr(167);
 			Expect(12);
 			break;
 		}
@@ -2376,12 +2385,12 @@ void AtomExpression(out Expr/*!*/ e) {
 			IfThenElseExpression(out e);
 			break;
 		}
-		case 113: {
+		case 114: {
 			CodeExpression(out locals, out blocks);
 			e = new CodeExpr(locals, blocks); 
 			break;
 		}
-		default: SynErr(167); break;
+		default: SynErr(168); break;
 		}
 	}
 
@@ -2393,7 +2402,7 @@ void Dec(out BigDec n) {
 		} else if (la.kind == 6) {
 			Get();
 			s = t.val; 
-		} else SynErr(168);
+		} else SynErr(169);
 		try {
 		 n = BigDec.FromString(s);
 		} catch (FormatException) {
@@ -2433,11 +2442,11 @@ void BvLit(out BigNum n, out int m) {
 	}
 
 	void Forall() {
-		if (la.kind == 116) {
+		if (la.kind == 117) {
 			Get();
-		} else if (la.kind == 117) {
+		} else if (la.kind == 118) {
 			Get();
-		} else SynErr(169);
+		} else SynErr(170);
 	}
 
 	void QuantifierBody(IToken/*!*/ q, out List<TypeVariable>/*!*/ typeParams, out List<Variable>/*!*/ ds,
@@ -2455,7 +2464,7 @@ void QuantifierBody(IToken/*!*/ q, out List<TypeVariable>/*!*/ typeParams, out L
 			}
 		} else if (StartOf(12)) {
 			BoundVars(out ds);
-		} else SynErr(170);
+		} else SynErr(171);
 		QSep();
 		while (la.kind == 26) {
 			AttributeOrTrigger(ref kv, ref trig);
@@ -2464,19 +2473,19 @@ void QuantifierBody(IToken/*!*/ q, out List<TypeVariable>/*!*/ typeParams, out L
 	}
 
 	void Exists() {
-		if (la.kind == 118) {
+		if (la.kind == 119) {
 			Get();
-		} else if (la.kind == 119) {
+		} else if (la.kind == 120) {
 			Get();
-		} else SynErr(171);
+		} else SynErr(172);
 	}
 
 	void Lambda() {
-		if (la.kind == 120) {
+		if (la.kind == 121) {
 			Get();
-		} else if (la.kind == 121) {
+		} else if (la.kind == 122) {
 			Get();
-		} else SynErr(172);
+		} else SynErr(173);
 	}
 
 	void LetExpr(out Expr/*!*/ letexpr) {
@@ -2497,7 +2506,7 @@ void LetExpr(out Expr/*!*/ letexpr) {
 			LetVar(out v);
 			ds.Add(v); 
 		}
-		Expect(68);
+		Expect(69);
 		Expression(out e0);
 		rhss.Add(e0); 
 		while (la.kind == 14) {
@@ -2521,7 +2530,7 @@ void IfThenElseExpression(out Expr/*!*/ e) {
 		Expect(56);
 		tok = t; 
 		Expression(out e0);
-		Expect(115);
+		Expect(116);
 		Expression(out e1);
 		Expect(57);
 		Expression(out e2);
@@ -2532,7 +2541,7 @@ void CodeExpression(out List<Variable>/*!*/ locals, out List<Block/*!*/>/*!*/ bl
 		Contract.Ensures(Contract.ValueAtReturn(out locals) != null); Contract.Ensures(cce.NonNullElements(Contract.ValueAtReturn(out blocks))); locals = new List<Variable>(); Block/*!*/ b;
 		blocks = new List<Block/*!*/>();
 		
-		Expect(113);
+		Expect(114);
 		while (la.kind == 9) {
 			LocalVars(locals);
 		}
@@ -2542,7 +2551,7 @@ void CodeExpression(out List<Variable>/*!*/ locals, out List<Block/*!*/>/*!*/ bl
 			SpecBlock(out b);
 			blocks.Add(b); 
 		}
-		Expect(114);
+		Expect(115);
 	}
 
 	void SpecBlock(out Block/*!*/ b) {
@@ -2579,7 +2588,7 @@ void SpecBlock(out Block/*!*/ b) {
 			Get();
 			Expression(out e);
 			b = new Block(x,x.val,cs,new ReturnExprCmd(t,e)); 
-		} else SynErr(173);
+		} else SynErr(174);
 		Expect(10);
 	}
 
@@ -2636,7 +2645,7 @@ void AttributeOrTrigger(ref QKeyValue kv, ref Trigger trig) {
 			 trig.AddLast(new Trigger(tok, true, es, null));
 			}
 			
-		} else SynErr(174);
+		} else SynErr(175);
 		Expect(27);
 	}
 
@@ -2651,15 +2660,15 @@ void AttributeParameter(out object/*!*/ o) {
 		} else if (StartOf(19)) {
 			Expression(out e);
 			o = e; 
-		} else SynErr(175);
+		} else SynErr(176);
 	}
 
 	void QSep() {
-		if (la.kind == 122) {
+		if (la.kind == 123) {
 			Get();
-		} else if (la.kind == 123) {
+		} else if (la.kind == 124) {
 			Get();
-		} else SynErr(176);
+		} else SynErr(177);
 	}
 
 	void LetVar(out Variable/*!*/ v) {
@@ -2688,33 +2697,33 @@ public void Parse() {
 	}
 
 	static readonly bool[,]/*!*/ set = {
-		{_T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _x,_x,_x,_x, _T,_x,_T,_T, _T,_x,_T,_x, _T,_T,_T,_x, _x,_x,_T,_T, _T,_T,_T,_x, _x,_x,_x,_T, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_T,_T, _x,_T,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
-		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x},
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+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _T,_x,_x,_x, _x,_x,_x,_T, _T,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _T,_x,_x,_x, _x,_x,_x,_T, _T,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_T,_T, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_T,_T, _T,_T,_T,_T, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _T,_x,_T,_T, _T,_x,_T,_x, _T,_T,_T,_T, _T,_T,_T,_T, _T,_x,_x,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_T,_T,_T, _T,_x,_x,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_T,_T, _T,_T,_T,_T, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_x, _x,_x,_x,_T, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_T, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_T, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_T,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_T, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_T,_T, _T,_T,_T,_T, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x},
+		{_x,_T,_T,_T, _T,_T,_T,_T, _x,_x,_x,_T, _x,_x,_x,_x, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_T,_T, _T,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _T,_x,_x,_x, _x,_T,_T,_T, _T,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_T,_x,_x, _x,_x,_x,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_T, _T,_T,_T,_x, _x,_x,_x,_x, _x,_x,_x,_x, _x,_x,_x}
 
 	};
 } // end Parser
@@ -2805,117 +2814,118 @@ string GetSyntaxErrorString(int n) {
 			case 63: s = "\"pop\" expected"; break;
 			case 64: s = "\"push\" expected"; break;
 			case 65: s = "\"assert\" expected"; break;
-			case 66: s = "\"assume\" expected"; break;
-			case 67: s = "\"havoc\" expected"; break;
-			case 68: s = "\":=\" expected"; break;
-			case 69: s = "\"->\" expected"; break;
-			case 70: s = "\"call\" expected"; break;
-			case 71: s = "\"par\" expected"; break;
-			case 72: s = "\"|\" expected"; break;
-			case 73: s = "\"<==>\" expected"; break;
-			case 74: s = "\"\\u21d4\" expected"; break;
-			case 75: s = "\"==>\" expected"; break;
-			case 76: s = "\"\\u21d2\" expected"; break;
-			case 77: s = "\"<==\" expected"; break;
-			case 78: s = "\"\\u21d0\" expected"; break;
-			case 79: s = "\"&&\" expected"; break;
-			case 80: s = "\"\\u2227\" expected"; break;
-			case 81: s = "\"||\" expected"; break;
-			case 82: s = "\"\\u2228\" expected"; break;
-			case 83: s = "\"==\" expected"; break;
-			case 84: s = "\"<=\" expected"; break;
-			case 85: s = "\">=\" expected"; break;
-			case 86: s = "\"!=\" expected"; break;
-			case 87: s = "\"\\u2260\" expected"; break;
-			case 88: s = "\"\\u2264\" expected"; break;
-			case 89: s = "\"\\u2265\" expected"; break;
-			case 90: s = "\"++\" expected"; break;
-			case 91: s = "\"+\" expected"; break;
-			case 92: s = "\"-\" expected"; break;
-			case 93: s = "\"div\" expected"; break;
-			case 94: s = "\"mod\" expected"; break;
-			case 95: s = "\"/\" expected"; break;
-			case 96: s = "\"**\" expected"; break;
-			case 97: s = "\"is\" expected"; break;
-			case 98: s = "\"!\" expected"; break;
-			case 99: s = "\"\\u00ac\" expected"; break;
-			case 100: s = "\"false\" expected"; break;
-			case 101: s = "\"true\" expected"; break;
-			case 102: s = "\"roundNearestTiesToEven\" expected"; break;
-			case 103: s = "\"RNE\" expected"; break;
-			case 104: s = "\"roundNearestTiesToAway\" expected"; break;
-			case 105: s = "\"RNA\" expected"; break;
-			case 106: s = "\"roundTowardPositive\" expected"; break;
-			case 107: s = "\"RTP\" expected"; break;
-			case 108: s = "\"roundTowardNegative\" expected"; break;
-			case 109: s = "\"RTN\" expected"; break;
-			case 110: s = "\"roundTowardZero\" expected"; break;
-			case 111: s = "\"RTZ\" expected"; break;
-			case 112: s = "\"old\" expected"; break;
-			case 113: s = "\"|{\" expected"; break;
-			case 114: s = "\"}|\" expected"; break;
-			case 115: s = "\"then\" expected"; break;
-			case 116: s = "\"forall\" expected"; break;
-			case 117: s = "\"\\u2200\" expected"; break;
-			case 118: s = "\"exists\" expected"; break;
-			case 119: s = "\"\\u2203\" expected"; break;
-			case 120: s = "\"lambda\" expected"; break;
-			case 121: s = "\"\\u03bb\" expected"; break;
-			case 122: s = "\"::\" expected"; break;
-			case 123: s = "\"\\u2022\" expected"; break;
-			case 124: s = "??? expected"; break;
-			case 125: s = "invalid BoogiePL"; break;
+			case 66: s = "\"check\" expected"; break;
+			case 67: s = "\"assume\" expected"; break;
+			case 68: s = "\"havoc\" expected"; break;
+			case 69: s = "\":=\" expected"; break;
+			case 70: s = "\"->\" expected"; break;
+			case 71: s = "\"call\" expected"; break;
+			case 72: s = "\"par\" expected"; break;
+			case 73: s = "\"|\" expected"; break;
+			case 74: s = "\"<==>\" expected"; break;
+			case 75: s = "\"\\u21d4\" expected"; break;
+			case 76: s = "\"==>\" expected"; break;
+			case 77: s = "\"\\u21d2\" expected"; break;
+			case 78: s = "\"<==\" expected"; break;
+			case 79: s = "\"\\u21d0\" expected"; break;
+			case 80: s = "\"&&\" expected"; break;
+			case 81: s = "\"\\u2227\" expected"; break;
+			case 82: s = "\"||\" expected"; break;
+			case 83: s = "\"\\u2228\" expected"; break;
+			case 84: s = "\"==\" expected"; break;
+			case 85: s = "\"<=\" expected"; break;
+			case 86: s = "\">=\" expected"; break;
+			case 87: s = "\"!=\" expected"; break;
+			case 88: s = "\"\\u2260\" expected"; break;
+			case 89: s = "\"\\u2264\" expected"; break;
+			case 90: s = "\"\\u2265\" expected"; break;
+			case 91: s = "\"++\" expected"; break;
+			case 92: s = "\"+\" expected"; break;
+			case 93: s = "\"-\" expected"; break;
+			case 94: s = "\"div\" expected"; break;
+			case 95: s = "\"mod\" expected"; break;
+			case 96: s = "\"/\" expected"; break;
+			case 97: s = "\"**\" expected"; break;
+			case 98: s = "\"is\" expected"; break;
+			case 99: s = "\"!\" expected"; break;
+			case 100: s = "\"\\u00ac\" expected"; break;
+			case 101: s = "\"false\" expected"; break;
+			case 102: s = "\"true\" expected"; break;
+			case 103: s = "\"roundNearestTiesToEven\" expected"; break;
+			case 104: s = "\"RNE\" expected"; break;
+			case 105: s = "\"roundNearestTiesToAway\" expected"; break;
+			case 106: s = "\"RNA\" expected"; break;
+			case 107: s = "\"roundTowardPositive\" expected"; break;
+			case 108: s = "\"RTP\" expected"; break;
+			case 109: s = "\"roundTowardNegative\" expected"; break;
+			case 110: s = "\"RTN\" expected"; break;
+			case 111: s = "\"roundTowardZero\" expected"; break;
+			case 112: s = "\"RTZ\" expected"; break;
+			case 113: s = "\"old\" expected"; break;
+			case 114: s = "\"|{\" expected"; break;
+			case 115: s = "\"}|\" expected"; break;
+			case 116: s = "\"then\" expected"; break;
+			case 117: s = "\"forall\" expected"; break;
+			case 118: s = "\"\\u2200\" expected"; break;
+			case 119: s = "\"exists\" expected"; break;
+			case 120: s = "\"\\u2203\" expected"; break;
+			case 121: s = "\"lambda\" expected"; break;
+			case 122: s = "\"\\u03bb\" expected"; break;
+			case 123: s = "\"::\" expected"; break;
+			case 124: s = "\"\\u2022\" expected"; break;
+			case 125: s = "??? expected"; break;
 			case 126: s = "invalid BoogiePL"; break;
-			case 127: s = "invalid Consts"; break;
-			case 128: s = "invalid Function"; break;
+			case 127: s = "invalid BoogiePL"; break;
+			case 128: s = "invalid Consts"; break;
 			case 129: s = "invalid Function"; break;
-			case 130: s = "invalid YieldProcedureDecl"; break;
-			case 131: s = "invalid Procedure"; break;
-			case 132: s = "invalid ActionDecl"; break;
-			case 133: s = "invalid Type"; break;
-			case 134: s = "invalid TypeAtom"; break;
-			case 135: s = "invalid Ident"; break;
-			case 136: s = "invalid TypeArgs"; break;
-			case 137: s = "invalid MoverQualifier"; break;
-			case 138: s = "invalid SpecAction"; break;
-			case 139: s = "invalid SpecYieldRequires"; break;
-			case 140: s = "invalid SpecYieldPrePost"; break;
-			case 141: s = "invalid SpecYieldEnsures"; break;
-			case 142: s = "invalid Spec"; break;
-			case 143: s = "invalid SpecPrePost"; break;
-			case 144: s = "invalid LabelOrCmd"; break;
+			case 130: s = "invalid Function"; break;
+			case 131: s = "invalid YieldProcedureDecl"; break;
+			case 132: s = "invalid Procedure"; break;
+			case 133: s = "invalid ActionDecl"; break;
+			case 134: s = "invalid Type"; break;
+			case 135: s = "invalid TypeAtom"; break;
+			case 136: s = "invalid Ident"; break;
+			case 137: s = "invalid TypeArgs"; break;
+			case 138: s = "invalid MoverQualifier"; break;
+			case 139: s = "invalid SpecAction"; break;
+			case 140: s = "invalid SpecYieldRequires"; break;
+			case 141: s = "invalid SpecYieldPrePost"; break;
+			case 142: s = "invalid SpecYieldEnsures"; break;
+			case 143: s = "invalid Spec"; break;
+			case 144: s = "invalid SpecPrePost"; break;
 			case 145: s = "invalid LabelOrCmd"; break;
-			case 146: s = "invalid StructuredCmd"; break;
-			case 147: s = "invalid TransferCmd"; break;
-			case 148: s = "invalid IfCmd"; break;
-			case 149: s = "invalid WhileCmd"; break;
-			case 150: s = "invalid Guard"; break;
-			case 151: s = "invalid LabelOrAssign"; break;
-			case 152: s = "invalid CallParams"; break;
-			case 153: s = "invalid EquivOp"; break;
-			case 154: s = "invalid ImpliesOp"; break;
-			case 155: s = "invalid ExpliesOp"; break;
-			case 156: s = "invalid AndOp"; break;
-			case 157: s = "invalid OrOp"; break;
-			case 158: s = "invalid RelOp"; break;
-			case 159: s = "invalid AddOp"; break;
-			case 160: s = "invalid MulOp"; break;
-			case 161: s = "invalid UnaryExpression"; break;
-			case 162: s = "invalid NegOp"; break;
-			case 163: s = "invalid CoercionExpression"; break;
-			case 164: s = "invalid ArrayExpression"; break;
-			case 165: s = "invalid AtomExpression"; break;
+			case 146: s = "invalid LabelOrCmd"; break;
+			case 147: s = "invalid StructuredCmd"; break;
+			case 148: s = "invalid TransferCmd"; break;
+			case 149: s = "invalid IfCmd"; break;
+			case 150: s = "invalid WhileCmd"; break;
+			case 151: s = "invalid Guard"; break;
+			case 152: s = "invalid LabelOrAssign"; break;
+			case 153: s = "invalid CallParams"; break;
+			case 154: s = "invalid EquivOp"; break;
+			case 155: s = "invalid ImpliesOp"; break;
+			case 156: s = "invalid ExpliesOp"; break;
+			case 157: s = "invalid AndOp"; break;
+			case 158: s = "invalid OrOp"; break;
+			case 159: s = "invalid RelOp"; break;
+			case 160: s = "invalid AddOp"; break;
+			case 161: s = "invalid MulOp"; break;
+			case 162: s = "invalid UnaryExpression"; break;
+			case 163: s = "invalid NegOp"; break;
+			case 164: s = "invalid CoercionExpression"; break;
+			case 165: s = "invalid ArrayExpression"; break;
 			case 166: s = "invalid AtomExpression"; break;
 			case 167: s = "invalid AtomExpression"; break;
-			case 168: s = "invalid Dec"; break;
-			case 169: s = "invalid Forall"; break;
-			case 170: s = "invalid QuantifierBody"; break;
-			case 171: s = "invalid Exists"; break;
-			case 172: s = "invalid Lambda"; break;
-			case 173: s = "invalid SpecBlock"; break;
-			case 174: s = "invalid AttributeOrTrigger"; break;
-			case 175: s = "invalid AttributeParameter"; break;
-			case 176: s = "invalid QSep"; break;
+			case 168: s = "invalid AtomExpression"; break;
+			case 169: s = "invalid Dec"; break;
+			case 170: s = "invalid Forall"; break;
+			case 171: s = "invalid QuantifierBody"; break;
+			case 172: s = "invalid Exists"; break;
+			case 173: s = "invalid Lambda"; break;
+			case 174: s = "invalid SpecBlock"; break;
+			case 175: s = "invalid AttributeOrTrigger"; break;
+			case 176: s = "invalid AttributeParameter"; break;
+			case 177: s = "invalid QSep"; break;
 
 			default: s = "error " + n; break;
 		}
diff --git a/Source/Core/Scanner.cs b/Source/Core/Scanner.cs
index 6bd51d22a..068c49517 100644
--- a/Source/Core/Scanner.cs
+++ b/Source/Core/Scanner.cs
@@ -220,8 +220,8 @@ public override int Read() {
 public class Scanner {
 	const char EOL = '\n';
 	const int eofSym = 0; /* pdt */
-	const int maxT = 124;
-	const int noSym = 124;
+	const int maxT = 125;
+	const int noSym = 125;
 
 
 	[ContractInvariantMethod]
@@ -558,30 +558,31 @@ void CheckLiteral() {
 			case "pop": t.kind = 63; break;
 			case "push": t.kind = 64; break;
 			case "assert": t.kind = 65; break;
-			case "assume": t.kind = 66; break;
-			case "havoc": t.kind = 67; break;
-			case "call": t.kind = 70; break;
-			case "par": t.kind = 71; break;
-			case "div": t.kind = 93; break;
-			case "mod": t.kind = 94; break;
-			case "is": t.kind = 97; break;
-			case "false": t.kind = 100; break;
-			case "true": t.kind = 101; break;
-			case "roundNearestTiesToEven": t.kind = 102; break;
-			case "RNE": t.kind = 103; break;
-			case "roundNearestTiesToAway": t.kind = 104; break;
-			case "RNA": t.kind = 105; break;
-			case "roundTowardPositive": t.kind = 106; break;
-			case "RTP": t.kind = 107; break;
-			case "roundTowardNegative": t.kind = 108; break;
-			case "RTN": t.kind = 109; break;
-			case "roundTowardZero": t.kind = 110; break;
-			case "RTZ": t.kind = 111; break;
-			case "old": t.kind = 112; break;
-			case "then": t.kind = 115; break;
-			case "forall": t.kind = 116; break;
-			case "exists": t.kind = 118; break;
-			case "lambda": t.kind = 120; break;
+			case "check": t.kind = 66; break;
+			case "assume": t.kind = 67; break;
+			case "havoc": t.kind = 68; break;
+			case "call": t.kind = 71; break;
+			case "par": t.kind = 72; break;
+			case "div": t.kind = 94; break;
+			case "mod": t.kind = 95; break;
+			case "is": t.kind = 98; break;
+			case "false": t.kind = 101; break;
+			case "true": t.kind = 102; break;
+			case "roundNearestTiesToEven": t.kind = 103; break;
+			case "RNE": t.kind = 104; break;
+			case "roundNearestTiesToAway": t.kind = 105; break;
+			case "RNA": t.kind = 106; break;
+			case "roundTowardPositive": t.kind = 107; break;
+			case "RTP": t.kind = 108; break;
+			case "roundTowardNegative": t.kind = 109; break;
+			case "RTN": t.kind = 110; break;
+			case "roundTowardZero": t.kind = 111; break;
+			case "RTZ": t.kind = 112; break;
+			case "old": t.kind = 113; break;
+			case "then": t.kind = 116; break;
+			case "forall": t.kind = 117; break;
+			case "exists": t.kind = 119; break;
+			case "lambda": t.kind = 121; break;
 			default: break;
 		}
 	}
@@ -865,67 +866,67 @@ void CheckLiteral() {
 			case 67:
 				{t.kind = 26; break;}
 			case 68:
-				{t.kind = 68; break;}
-			case 69:
 				{t.kind = 69; break;}
+			case 69:
+				{t.kind = 70; break;}
 			case 70:
-				{t.kind = 73; break;}
-			case 71:
 				{t.kind = 74; break;}
-			case 72:
+			case 71:
 				{t.kind = 75; break;}
-			case 73:
+			case 72:
 				{t.kind = 76; break;}
+			case 73:
+				{t.kind = 77; break;}
 			case 74:
-				{t.kind = 78; break;}
+				{t.kind = 79; break;}
 			case 75:
 				if (ch == '&') {AddCh(); goto case 76;}
 				else {goto case 0;}
 			case 76:
-				{t.kind = 79; break;}
-			case 77:
 				{t.kind = 80; break;}
-			case 78:
+			case 77:
 				{t.kind = 81; break;}
-			case 79:
+			case 78:
 				{t.kind = 82; break;}
+			case 79:
+				{t.kind = 83; break;}
 			case 80:
-				{t.kind = 85; break;}
-			case 81:
 				{t.kind = 86; break;}
-			case 82:
+			case 81:
 				{t.kind = 87; break;}
-			case 83:
+			case 82:
 				{t.kind = 88; break;}
-			case 84:
+			case 83:
 				{t.kind = 89; break;}
-			case 85:
+			case 84:
 				{t.kind = 90; break;}
+			case 85:
+				{t.kind = 91; break;}
 			case 86:
-				{t.kind = 95; break;}
-			case 87:
 				{t.kind = 96; break;}
+			case 87:
+				{t.kind = 97; break;}
 			case 88:
-				{t.kind = 99; break;}
+				{t.kind = 100; break;}
 			case 89:
-				{t.kind = 113; break;}
-			case 90:
 				{t.kind = 114; break;}
+			case 90:
+				{t.kind = 115; break;}
 			case 91:
-				{t.kind = 117; break;}
+				{t.kind = 118; break;}
 			case 92:
-				{t.kind = 119; break;}
+				{t.kind = 120; break;}
 			case 93:
-				{t.kind = 121; break;}
-			case 94:
 				{t.kind = 122; break;}
-			case 95:
+			case 94:
 				{t.kind = 123; break;}
+			case 95:
+				{t.kind = 124; break;}
 			case 96:
-				recEnd = pos; recKind = 92;
+				recEnd = pos; recKind = 93;
 				if (ch == '0') {AddCh(); goto case 16;}
 				else if (ch == '>') {AddCh(); goto case 69;}
-				else {t.kind = 92; break;}
+				else {t.kind = 93; break;}
 			case 97:
 				recEnd = pos; recKind = 13;
 				if (ch == '=') {AddCh(); goto case 68;}
@@ -952,30 +953,30 @@ void CheckLiteral() {
 				if (ch == '*') {AddCh(); goto case 87;}
 				else {t.kind = 59; break;}
 			case 103:
-				recEnd = pos; recKind = 72;
+				recEnd = pos; recKind = 73;
 				if (ch == '|') {AddCh(); goto case 78;}
 				else if (ch == '{') {AddCh(); goto case 89;}
-				else {t.kind = 72; break;}
+				else {t.kind = 73; break;}
 			case 104:
-				recEnd = pos; recKind = 98;
+				recEnd = pos; recKind = 99;
 				if (ch == '=') {AddCh(); goto case 81;}
-				else {t.kind = 98; break;}
+				else {t.kind = 99; break;}
 			case 105:
-				recEnd = pos; recKind = 91;
+				recEnd = pos; recKind = 92;
 				if (ch == '+') {AddCh(); goto case 85;}
-				else {t.kind = 91; break;}
+				else {t.kind = 92; break;}
 			case 106:
-				recEnd = pos; recKind = 84;
+				recEnd = pos; recKind = 85;
 				if (ch == '=') {AddCh(); goto case 108;}
-				else {t.kind = 84; break;}
+				else {t.kind = 85; break;}
 			case 107:
-				recEnd = pos; recKind = 83;
+				recEnd = pos; recKind = 84;
 				if (ch == '>') {AddCh(); goto case 72;}
-				else {t.kind = 83; break;}
+				else {t.kind = 84; break;}
 			case 108:
-				recEnd = pos; recKind = 77;
+				recEnd = pos; recKind = 78;
 				if (ch == '>') {AddCh(); goto case 70;}
-				else {t.kind = 77; break;}
+				else {t.kind = 78; break;}
 
 		}
 		t.val = new String(tval, 0, tlen);
diff --git a/Source/VCGeneration/CommandTransformations.cs b/Source/VCGeneration/CommandTransformations.cs
index 114fa805a..bef142df2 100644
--- a/Source/VCGeneration/CommandTransformations.cs
+++ b/Source/VCGeneration/CommandTransformations.cs
@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+using System.Linq;
 using Microsoft.Boogie;
 using VC;
 
@@ -5,13 +7,14 @@ namespace VCGeneration;
 
 public static class CommandTransformations
 {
-  public static Cmd AssertIntoAssume(VCGenOptions options, Cmd c)
+  public static IEnumerable<Cmd> AssertIntoAssumes(VCGenOptions options, Cmd cmd)
   {
-    if (c is AssertCmd assertCmd)
-    {
-      return VerificationConditionGenerator.AssertTurnedIntoAssume(options, assertCmd);
+    if (cmd is AssertCmd assertCmd) {
+      return assertCmd.Remember 
+        ? new[] { VerificationConditionGenerator.AssertTurnedIntoAssume(options, assertCmd) } 
+        : Enumerable.Empty<Cmd>();
     }
 
-    return c;
+    return new[] {cmd};
   }
 }
\ No newline at end of file
diff --git a/Source/VCGeneration/FocusAttribute.cs b/Source/VCGeneration/FocusAttribute.cs
index ebaeedf60..c1f7a734e 100644
--- a/Source/VCGeneration/FocusAttribute.cs
+++ b/Source/VCGeneration/FocusAttribute.cs
@@ -59,7 +59,7 @@ void FocusRec(IToken focusToken, int focusIndex, IReadOnlyList<Block> blocksToIn
           // Their assertions turn into assumes and any splits inside them are disabled.
           if(freeAssumeBlocks.Contains(block))
           {
-            newBlock.Cmds = block.Cmds.Select(c => CommandTransformations.AssertIntoAssume(options, c)).Select(DisableSplits).ToList();
+            newBlock.Cmds = block.Cmds.SelectMany(c => CommandTransformations.AssertIntoAssumes(options, c)).Select(DisableSplits).ToList();
           }
           if (block.TransferCmd is GotoCmd gtc)
           {
diff --git a/Source/VCGeneration/ManualSplitFinder.cs b/Source/VCGeneration/ManualSplitFinder.cs
index 41bd02472..cdb0e1f66 100644
--- a/Source/VCGeneration/ManualSplitFinder.cs
+++ b/Source/VCGeneration/ManualSplitFinder.cs
@@ -112,7 +112,12 @@ private static List<Block> DoPreAssignedManualSplit(VCGenOptions options, List<B
             splitCount++;
             verify = splitCount == splitNumberWithinBlock;
           }
-          newCmds.Add(verify ? command : CommandTransformations.AssertIntoAssume(options, command));
+
+          if (verify) {
+            newCmds.Add(command);
+          } else {
+            newCmds.AddRange(CommandTransformations.AssertIntoAssumes(options, command));
+          }
         }
         newBlock.Cmds = newCmds;
       } else if (lastSplitInBlock && blockAssignments[currentBlock] == containingBlock) {
@@ -120,11 +125,15 @@ private static List<Block> DoPreAssignedManualSplit(VCGenOptions options, List<B
         var newCmds = new List<Cmd>();
         foreach (Cmd command in currentBlock.Cmds) {
           verify = !ShouldSplitHere(command, splitOnEveryAssert) && verify;
-          newCmds.Add(verify ? command : CommandTransformations.AssertIntoAssume(options, command));
+          if (verify) {
+            newCmds.Add(command);
+          } else {
+            newCmds.AddRange(CommandTransformations.AssertIntoAssumes(options, command));
+          }
         }
         newBlock.Cmds = newCmds;
       } else {
-        newBlock.Cmds = currentBlock.Cmds.Select(x => CommandTransformations.AssertIntoAssume(options, x)).ToList();
+        newBlock.Cmds = currentBlock.Cmds.SelectMany(cmd => CommandTransformations.AssertIntoAssumes(options, cmd)).ToList();
       }
     }
     // Patch the edges between the new blocks
diff --git a/Source/VCGeneration/VerificationConditionGenerator.cs b/Source/VCGeneration/VerificationConditionGenerator.cs
index bdff1b0f2..13cb94928 100644
--- a/Source/VCGeneration/VerificationConditionGenerator.cs
+++ b/Source/VCGeneration/VerificationConditionGenerator.cs
@@ -82,10 +82,6 @@ public static AssumeCmd AssertTurnedIntoAssume(VCGenOptions options, AssertCmd a
       return assume;
     }
 
-    #region Soundness smoke tester
-
-    #endregion
-
     public class CodeExprConversionClosure
     {
       private readonly TextWriter traceWriter;
diff --git a/Test/test0/Split/Foo.split.1.bpl.expect b/Test/test0/Split/Foo.split.1.bpl.expect
index bc4ea17f5..46c752201 100644
--- a/Test/test0/Split/Foo.split.1.bpl.expect
+++ b/Test/test0/Split/Foo.split.1.bpl.expect
@@ -23,7 +23,7 @@ implementation Foo() returns (y: int)
 
   anon6_Then:
     assume {:partition} x#AT#1 < 3;
-    assert 2 < 2;
+    check 2 < 2;
     assume y#AT#1 * y#AT#1 > 4;
     goto ;
 }
diff --git a/Test/test0/Split/Foo.split.2.bpl.expect b/Test/test0/Split/Foo.split.2.bpl.expect
index b07405c80..39301f352 100644
--- a/Test/test0/Split/Foo.split.2.bpl.expect
+++ b/Test/test0/Split/Foo.split.2.bpl.expect
@@ -23,7 +23,7 @@ implementation Foo() returns (y: int)
 
   anon6_Else:
     assume {:partition} 3 <= x#AT#1;
-    assert {:split_here} y#AT#1 * y#AT#1 * y#AT#1 < 8;
+    check {:split_here} y#AT#1 * y#AT#1 * y#AT#1 < 8;
     assert 2 < 2;
     goto ;
 }
diff --git a/Test/test0/Split/Foo.split.3.bpl.expect b/Test/test0/Split/Foo.split.3.bpl.expect
index 9ef24510f..b71832fb4 100644
--- a/Test/test0/Split/Foo.split.3.bpl.expect
+++ b/Test/test0/Split/Foo.split.3.bpl.expect
@@ -23,7 +23,6 @@ implementation Foo() returns (y: int)
 
   anon6_Else:
     assume {:partition} 3 <= x#AT#1;
-    assume y#AT#1 * y#AT#1 * y#AT#1 < 8;
     assume 2 < 2;
     goto anon4;
 
@@ -36,7 +35,6 @@ implementation Foo() returns (y: int)
 
   anon6_Then:
     assume {:partition} x#AT#1 < 3;
-    assume 2 < 2;
     assume y#AT#1 * y#AT#1 > 4;
     goto anon4;
 }
diff --git a/Test/test0/Split/Split.bpl b/Test/test0/Split/Split.bpl
index e99d76351..82493b214 100644
--- a/Test/test0/Split/Split.bpl
+++ b/Test/test0/Split/Split.bpl
@@ -19,11 +19,11 @@ procedure Foo() returns (y: int)
     assert {:split_here} (x+y) * (x+y) > 25;
     y := y + 1;
     if (x < 3) {
-      assert 2 < 2;
+      check 2 < 2;
       assert {:split_here} y*y > 4;
     }
     else {
-      assert {:split_here} y*y*y < 8;
+      check {:split_here} y*y*y < 8;
       assert 2 < 2;
     }
     assert {:split_here} (x+y) * (x+y) == 25;

From 49f48cf2e22a570f194e1cfa99a71180d88d98f4 Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 26 Aug 2024 15:07:30 +0200
Subject: [PATCH 2/9] Add blank line

---
 Source/VCGeneration/ManualSplitFinder.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Source/VCGeneration/ManualSplitFinder.cs b/Source/VCGeneration/ManualSplitFinder.cs
index 8967a3b25..12b3a705f 100644
--- a/Source/VCGeneration/ManualSplitFinder.cs
+++ b/Source/VCGeneration/ManualSplitFinder.cs
@@ -120,6 +120,7 @@ private static List<Block> SplitOnAssert(VCGenOptions options, List<Block> oldBl
     AddBlockJumps(oldBlocks, oldToNewBlockMap);
     return newBlocks;
   }
+  
   private static List<Block>? DoPreAssignedManualSplit(VCGenOptions options, List<Block> blocks, 
     Dictionary<Block, Block> blockAssignments, int splitNumberWithinBlock,
     Block containingBlock, bool lastSplitInBlock, bool splitOnEveryAssert) {

From f9cf8072b2bac78027f052cadb9a56fbd7b8e1d6 Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 16 Sep 2024 14:15:51 +0200
Subject: [PATCH 3/9] Move structured commands into separate files

---
 Source/Core/AST/AbsyCmd.cs                    | 761 ------------------
 Source/Core/AST/BigBlocksResolutionContext.cs | 591 ++++++++++++++
 .../Core/AST/StructuredCommands/ByProofCmd.cs |  16 +
 Source/Core/AST/StructuredCommands/IfCmd.cs   | 108 +++
 .../Core/AST/StructuredCommands/WhileCmd.cs   |  74 ++
 5 files changed, 789 insertions(+), 761 deletions(-)
 create mode 100644 Source/Core/AST/BigBlocksResolutionContext.cs
 create mode 100644 Source/Core/AST/StructuredCommands/ByProofCmd.cs
 create mode 100644 Source/Core/AST/StructuredCommands/IfCmd.cs
 create mode 100644 Source/Core/AST/StructuredCommands/WhileCmd.cs

diff --git a/Source/Core/AST/AbsyCmd.cs b/Source/Core/AST/AbsyCmd.cs
index b64271504..24ace542c 100644
--- a/Source/Core/AST/AbsyCmd.cs
+++ b/Source/Core/AST/AbsyCmd.cs
@@ -351,592 +351,6 @@ public void AddLocalVariable(string name)
     }
   }
 
-  class BigBlocksResolutionContext
-  {
-    StmtList /*!*/
-      stmtList;
-
-    [Peer] List<Block /*!*/> blocks;
-
-    string /*!*/
-      prefix = "anon";
-
-    int anon = 0;
-
-    int FreshAnon()
-    {
-      return anon++;
-    }
-
-    HashSet<string /*!*/> allLabels = new HashSet<string /*!*/>();
-
-    Errors /*!*/
-      errorHandler;
-
-    [ContractInvariantMethod]
-    void ObjectInvariant()
-    {
-      Contract.Invariant(stmtList != null);
-      Contract.Invariant(cce.NonNullElements(blocks, true));
-      Contract.Invariant(prefix != null);
-      Contract.Invariant(cce.NonNullElements(allLabels, true));
-      Contract.Invariant(errorHandler != null);
-    }
-
-    private void ComputeAllLabels(StmtList stmts)
-    {
-      if (stmts == null)
-      {
-        return;
-      }
-
-      foreach (BigBlock bb in stmts.BigBlocks)
-      {
-        if (bb.LabelName != null)
-        {
-          allLabels.Add(bb.LabelName);
-        }
-
-        ComputeAllLabels(bb.ec);
-      }
-    }
-
-    private void ComputeAllLabels(StructuredCmd cmd)
-    {
-      if (cmd == null)
-      {
-        return;
-      }
-
-      if (cmd is IfCmd)
-      {
-        IfCmd ifCmd = (IfCmd) cmd;
-        ComputeAllLabels(ifCmd.thn);
-        ComputeAllLabels(ifCmd.elseIf);
-        ComputeAllLabels(ifCmd.elseBlock);
-      }
-      else if (cmd is WhileCmd)
-      {
-        WhileCmd whileCmd = (WhileCmd) cmd;
-        ComputeAllLabels(whileCmd.Body);
-      }
-    }
-
-    public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
-    {
-      Contract.Requires(errorHandler != null);
-      Contract.Requires(stmtList != null);
-      this.stmtList = stmtList;
-      // Inject an empty big block at the end of the body of a while loop if its current end is another while loop.
-      // This transformation creates a suitable jump target for break statements inside the nested while loop.
-      InjectEmptyBigBlockInsideWhileLoopBody(stmtList);
-      this.errorHandler = errorHandler;
-      ComputeAllLabels(stmtList);
-    }
-
-    public List<Block /*!*/> /*!*/ Blocks
-    {
-      get
-      {
-        Contract.Ensures(cce.NonNullElements(Contract.Result<List<Block>>()));
-        if (blocks == null)
-        {
-          blocks = new List<Block /*!*/>();
-
-          int startErrorCount = this.errorHandler.count;
-          // Check that all goto statements go to a label in allLabels, and no break statement to a non-enclosing loop.
-          // Also, determine a good value for "prefix".
-          CheckLegalLabels(stmtList, null, null);
-
-          // fill in names of anonymous blocks
-          NameAnonymousBlocks(stmtList);
-
-          // determine successor blocks
-          RecordSuccessors(stmtList, null);
-
-          if (this.errorHandler.count == startErrorCount)
-          {
-            // generate blocks from the big blocks
-            CreateBlocks(stmtList, null);
-          }
-        }
-
-        return blocks;
-      }
-    }
-
-    void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
-    {
-      foreach (var bb in stmtList.BigBlocks)
-      {
-        InjectEmptyBigBlockInsideWhileLoopBody(bb.ec);
-      }
-    }
-
-    void InjectEmptyBigBlockInsideWhileLoopBody(StructuredCmd structuredCmd)
-    {
-      if (structuredCmd is WhileCmd whileCmd)
-      {
-        InjectEmptyBigBlockInsideWhileLoopBody(whileCmd.Body);
-        if (whileCmd.Body.BigBlocks.Count > 0 && whileCmd.Body.BigBlocks.Last().ec is WhileCmd)
-        {
-          var newBigBlocks = new List<BigBlock>(whileCmd.Body.BigBlocks);
-          newBigBlocks.Add(new BigBlock(Token.NoToken, null, new List<Cmd>(), null, null));
-          whileCmd.Body = new StmtList(newBigBlocks, whileCmd.Body.EndCurly);
-        }
-      }
-      else if (structuredCmd is IfCmd ifCmd)
-      {
-        InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.thn);
-        if (ifCmd.elseBlock != null)
-        {
-          InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseBlock);
-        }
-
-        if (ifCmd.elseIf != null)
-        {
-          InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseIf);
-        }
-      }
-    }
-
-    void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
-    {
-      Contract.Requires(stmtList != null);
-      Contract.Requires((parentContext == null) == (parentBigBlock == null));
-      Contract.Requires(stmtList.ParentContext == null); // it hasn't been set yet
-      //modifies stmtList.*;
-      Contract.Ensures(stmtList.ParentContext == parentContext);
-      stmtList.ParentContext = parentContext;
-      stmtList.ParentBigBlock = parentBigBlock;
-
-      // record the labels declared in this StmtList
-      foreach (BigBlock b in stmtList.BigBlocks)
-      {
-        if (b.LabelName != null)
-        {
-          string n = b.LabelName;
-          if (n.StartsWith(prefix))
-          {
-            if (prefix.Length < n.Length && n[prefix.Length] == '0')
-            {
-              prefix += "1";
-            }
-            else
-            {
-              prefix += "0";
-            }
-          }
-
-          stmtList.AddLabel(b.LabelName);
-        }
-      }
-
-      // check that labels in this and nested StmtList's are legal
-      foreach (BigBlock b in stmtList.BigBlocks)
-      {
-        // goto's must reference blocks in enclosing blocks
-        if (b.tc is GotoCmd)
-        {
-          GotoCmd g = (GotoCmd) b.tc;
-          foreach (string /*!*/ lbl in cce.NonNull(g.labelNames))
-          {
-            Contract.Assert(lbl != null);
-            /*
-            bool found = false;
-            for (StmtList sl = stmtList; sl != null; sl = sl.ParentContext) {
-              if (sl.Labels.Contains(lbl)) {
-                found = true;
-                break;
-              }
-            }
-            if (!found) {
-              this.errorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined or out of reach");
-            }
-            */
-            if (!allLabels.Contains(lbl))
-            {
-              this.errorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined");
-            }
-          }
-        }
-
-        // break labels must refer to an enclosing while statement
-        else if (b.ec is BreakCmd)
-        {
-          BreakCmd bcmd = (BreakCmd) b.ec;
-          Contract.Assert(bcmd.BreakEnclosure == null); // it hasn't been initialized yet
-          bool found = false;
-          for (StmtList sl = stmtList; sl.ParentBigBlock != null; sl = sl.ParentContext)
-          {
-            cce.LoopInvariant(sl != null);
-            BigBlock bb = sl.ParentBigBlock;
-
-            if (bcmd.Label == null)
-            {
-              // a label-less break statement breaks out of the innermost enclosing while statement
-              if (bb.ec is WhileCmd)
-              {
-                bcmd.BreakEnclosure = bb;
-                found = true;
-                break;
-              }
-            }
-            else if (bcmd.Label == bb.LabelName)
-            {
-              // a break statement with a label can break out of both if statements and while statements
-              if (bb.simpleCmds.Count == 0)
-              {
-                // this is a good target:  the label refers to the if/while statement
-                bcmd.BreakEnclosure = bb;
-              }
-              else
-              {
-                // the label of bb refers to the first statement of bb, which in which case is a simple statement, not an if/while statement
-                this.errorHandler.SemErr(bcmd.tok,
-                  "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
-              }
-
-              found = true; // don't look any further, since we've found a matching label
-              break;
-            }
-          }
-
-          if (!found)
-          {
-            if (bcmd.Label == null)
-            {
-              this.errorHandler.SemErr(bcmd.tok, "Error: break statement is not inside a loop");
-            }
-            else
-            {
-              this.errorHandler.SemErr(bcmd.tok,
-                "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
-            }
-          }
-        }
-
-        // recurse
-        else if (b.ec is WhileCmd)
-        {
-          WhileCmd wcmd = (WhileCmd) b.ec;
-          CheckLegalLabels(wcmd.Body, stmtList, b);
-        }
-        else
-        {
-          for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-          {
-            CheckLegalLabels(ifcmd.thn, stmtList, b);
-            if (ifcmd.elseBlock != null)
-            {
-              CheckLegalLabels(ifcmd.elseBlock, stmtList, b);
-            }
-          }
-        }
-      }
-    }
-
-    void NameAnonymousBlocks(StmtList stmtList)
-    {
-      Contract.Requires(stmtList != null);
-      foreach (BigBlock b in stmtList.BigBlocks)
-      {
-        if (b.LabelName == null)
-        {
-          b.LabelName = prefix + FreshAnon();
-        }
-
-        if (b.ec is WhileCmd)
-        {
-          WhileCmd wcmd = (WhileCmd) b.ec;
-          NameAnonymousBlocks(wcmd.Body);
-        }
-        else
-        {
-          for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-          {
-            NameAnonymousBlocks(ifcmd.thn);
-            if (ifcmd.elseBlock != null)
-            {
-              NameAnonymousBlocks(ifcmd.elseBlock);
-            }
-          }
-        }
-      }
-    }
-
-    void RecordSuccessors(StmtList stmtList, BigBlock successor)
-    {
-      Contract.Requires(stmtList != null);
-      for (int i = stmtList.BigBlocks.Count; 0 <= --i;)
-      {
-        BigBlock big = stmtList.BigBlocks[i];
-        big.successorBigBlock = successor;
-
-        if (big.ec is WhileCmd)
-        {
-          WhileCmd wcmd = (WhileCmd) big.ec;
-          RecordSuccessors(wcmd.Body, big);
-        }
-        else
-        {
-          for (IfCmd ifcmd = big.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-          {
-            RecordSuccessors(ifcmd.thn, successor);
-            if (ifcmd.elseBlock != null)
-            {
-              RecordSuccessors(ifcmd.elseBlock, successor);
-            }
-          }
-        }
-
-        successor = big;
-      }
-    }
-
-    // If the enclosing context is a loop, then "runOffTheEndLabel" is the loop head label;
-    // otherwise, it is null.
-    void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
-    {
-      Contract.Requires(stmtList != null);
-      Contract.Requires(blocks != null);
-      List<Cmd> cmdPrefixToApply = stmtList.PrefixCommands;
-
-      int n = stmtList.BigBlocks.Count;
-      foreach (BigBlock b in stmtList.BigBlocks)
-      {
-        n--;
-        Contract.Assert(b.LabelName != null);
-        List<Cmd> theSimpleCmds;
-        if (cmdPrefixToApply == null)
-        {
-          theSimpleCmds = b.simpleCmds;
-        }
-        else
-        {
-          theSimpleCmds = new List<Cmd>();
-          theSimpleCmds.AddRange(cmdPrefixToApply);
-          theSimpleCmds.AddRange(b.simpleCmds);
-          cmdPrefixToApply = null; // now, we've used 'em up
-        }
-
-        if (b.tc != null)
-        {
-          // this BigBlock has the very same components as a Block
-          Contract.Assert(b.ec == null);
-          Block block = new Block(b.tok, b.LabelName, theSimpleCmds, b.tc);
-          blocks.Add(block);
-        }
-        else if (b.ec == null)
-        {
-          TransferCmd trCmd;
-          if (n == 0 && runOffTheEndLabel != null)
-          {
-            // goto the given label instead of the textual successor block
-            trCmd = new GotoCmd(stmtList.EndCurly, new List<String> {runOffTheEndLabel});
-          }
-          else
-          {
-            trCmd = GotoSuccessor(stmtList.EndCurly, b);
-          }
-
-          Block block = new Block(b.tok, b.LabelName, theSimpleCmds, trCmd);
-          blocks.Add(block);
-        }
-        else if (b.ec is BreakCmd)
-        {
-          BreakCmd bcmd = (BreakCmd) b.ec;
-          Contract.Assert(bcmd.BreakEnclosure != null);
-          Block block = new Block(b.tok, b.LabelName, theSimpleCmds, GotoSuccessor(b.ec.tok, bcmd.BreakEnclosure));
-          blocks.Add(block);
-        }
-        else if (b.ec is WhileCmd)
-        {
-          WhileCmd wcmd = (WhileCmd) b.ec;
-          var a = FreshAnon();
-          string loopHeadLabel = prefix + a + "_LoopHead";
-          string /*!*/
-            loopBodyLabel = prefix + a + "_LoopBody";
-          string loopDoneLabel = prefix + a + "_LoopDone";
-
-          List<Cmd> ssBody = new List<Cmd>();
-          List<Cmd> ssDone = new List<Cmd>();
-          if (wcmd.Guard != null)
-          {
-            var ac = new AssumeCmd(wcmd.tok, wcmd.Guard);
-            ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-            ssBody.Add(ac);
-
-            ac = new AssumeCmd(wcmd.tok, Expr.Not(wcmd.Guard));
-            ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-            ssDone.Add(ac);
-          }
-
-          // Try to squeeze in ssBody into the first block of wcmd.Body
-          bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
-
-          // ... goto LoopHead;
-          Block block = new Block(b.tok, b.LabelName, theSimpleCmds,
-            new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
-          blocks.Add(block);
-
-          // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
-          List<Cmd> ssHead = new List<Cmd>();
-          foreach (CallCmd yield in wcmd.Yields)
-          {
-            ssHead.Add(yield);
-          }
-          foreach (PredicateCmd inv in wcmd.Invariants)
-          {
-            ssHead.Add(inv);
-          }
-
-          block = new Block(wcmd.tok, loopHeadLabel, ssHead,
-            new GotoCmd(wcmd.tok, new List<String> {loopDoneLabel, loopBodyLabel}));
-          blocks.Add(block);
-
-          if (!bodyGuardTakenCareOf)
-          {
-            // LoopBody: assume guard; goto firstLoopBlock;
-            block = new Block(wcmd.tok, loopBodyLabel, ssBody,
-              new GotoCmd(wcmd.tok, new List<String> {wcmd.Body.BigBlocks[0].LabelName}));
-            blocks.Add(block);
-          }
-
-          // recurse to create the blocks for the loop body
-          CreateBlocks(wcmd.Body, loopHeadLabel);
-
-          // LoopDone: assume !guard; goto loopSuccessor;
-          TransferCmd trCmd;
-          if (n == 0 && runOffTheEndLabel != null)
-          {
-            // goto the given label instead of the textual successor block
-            trCmd = new GotoCmd(wcmd.tok, new List<String> {runOffTheEndLabel});
-          }
-          else
-          {
-            trCmd = GotoSuccessor(wcmd.tok, b);
-          }
-
-          block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
-          blocks.Add(block);
-        }
-        else
-        {
-          IfCmd ifcmd = (IfCmd) b.ec;
-          string predLabel = b.LabelName;
-          List<Cmd> predCmds = theSimpleCmds;
-
-          for (; ifcmd != null; ifcmd = ifcmd.elseIf)
-          {
-            var a = FreshAnon();
-            string thenLabel = prefix + a + "_Then";
-            Contract.Assert(thenLabel != null);
-            string elseLabel = prefix + a + "_Else";
-            Contract.Assert(elseLabel != null);
-
-            List<Cmd> ssThen = new List<Cmd>();
-            List<Cmd> ssElse = new List<Cmd>();
-            if (ifcmd.Guard != null)
-            {
-              var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard);
-              ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-              ssThen.Add(ac);
-
-              ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-              ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-              ssElse.Add(ac);
-            }
-
-            // Try to squeeze in ssThen/ssElse into the first block of ifcmd.thn/ifcmd.elseBlock
-            bool thenGuardTakenCareOf = ifcmd.thn.PrefixFirstBlock(ssThen, ref thenLabel);
-            bool elseGuardTakenCareOf = false;
-            if (ifcmd.elseBlock != null)
-            {
-              elseGuardTakenCareOf = ifcmd.elseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
-            }
-
-            // ... goto Then, Else;
-            var jumpBlock = new Block(b.tok, predLabel, predCmds,
-              new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
-            blocks.Add(jumpBlock);
-
-            if (!thenGuardTakenCareOf)
-            {
-              // Then: assume guard; goto firstThenBlock;
-              var thenJumpBlock = new Block(ifcmd.tok, thenLabel, ssThen,
-                new GotoCmd(ifcmd.tok, new List<String> {ifcmd.thn.BigBlocks[0].LabelName}));
-              blocks.Add(thenJumpBlock);
-            }
-
-            // recurse to create the blocks for the then branch
-            CreateBlocks(ifcmd.thn, n == 0 ? runOffTheEndLabel : null);
-
-            if (ifcmd.elseBlock != null)
-            {
-              Contract.Assert(ifcmd.elseIf == null);
-              if (!elseGuardTakenCareOf)
-              {
-                // Else: assume !guard; goto firstElseBlock;
-                var elseJumpBlock = new Block(ifcmd.tok, elseLabel, ssElse,
-                  new GotoCmd(ifcmd.tok, new List<String> {ifcmd.elseBlock.BigBlocks[0].LabelName}));
-                blocks.Add(elseJumpBlock);
-              }
-
-              // recurse to create the blocks for the else branch
-              CreateBlocks(ifcmd.elseBlock, n == 0 ? runOffTheEndLabel : null);
-            }
-            else if (ifcmd.elseIf != null)
-            {
-              // this is an "else if"
-              predLabel = elseLabel;
-              predCmds = new List<Cmd>();
-              if (ifcmd.Guard != null)
-              {
-                var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-                ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-                predCmds.Add(ac);
-              }
-            }
-            else
-            {
-              // no else alternative is specified, so else branch is just "skip"
-              // Else: assume !guard; goto ifSuccessor;
-              TransferCmd trCmd;
-              if (n == 0 && runOffTheEndLabel != null)
-              {
-                // goto the given label instead of the textual successor block
-                trCmd = new GotoCmd(ifcmd.tok, new List<String> {runOffTheEndLabel});
-              }
-              else
-              {
-                trCmd = GotoSuccessor(ifcmd.tok, b);
-              }
-
-              var block = new Block(ifcmd.tok, elseLabel, ssElse, trCmd);
-              blocks.Add(block);
-            }
-          }
-        }
-      }
-    }
-
-    TransferCmd GotoSuccessor(IToken tok, BigBlock b)
-    {
-      Contract.Requires(b != null);
-      Contract.Requires(tok != null);
-      Contract.Ensures(Contract.Result<TransferCmd>() != null);
-      if (b.successorBigBlock != null)
-      {
-        return new GotoCmd(tok, new List<String> {b.successorBigBlock.LabelName});
-      }
-      else
-      {
-        return new ReturnCmd(tok);
-      }
-    }
-  }
-
   [ContractClass(typeof(StructuredCmdContracts))]
   public abstract class StructuredCmd
   {
@@ -986,181 +400,6 @@ public StructuredCmdContracts() : base(null)
     }
   }
 
-  public class IfCmd : StructuredCmd
-  {
-    public Expr Guard;
-
-    private StmtList /*!*/
-      _thn;
-
-    public StmtList /*!*/ thn
-    {
-      get
-      {
-        Contract.Ensures(Contract.Result<StmtList>() != null);
-        return this._thn;
-      }
-      set
-      {
-        Contract.Requires(value != null);
-        this._thn = value;
-      }
-    }
-
-    private IfCmd _elseIf;
-
-    public IfCmd elseIf
-    {
-      get { return this._elseIf; }
-      set
-      {
-        Contract.Requires(value == null || this.elseBlock == null);
-        this._elseIf = value;
-      }
-    }
-
-    private StmtList _elseBlock;
-
-    public StmtList elseBlock
-    {
-      get { return this._elseBlock; }
-      set
-      {
-        Contract.Requires(value == null || this.elseIf == null);
-        this._elseBlock = value;
-      }
-    }
-
-    [ContractInvariantMethod]
-    void ObjectInvariant()
-    {
-      Contract.Invariant(this._thn != null);
-      Contract.Invariant(this._elseIf == null || this._elseBlock == null);
-    }
-
-    public IfCmd(IToken /*!*/ tok, Expr guard, StmtList /*!*/ thn, IfCmd elseIf, StmtList elseBlock)
-      : base(tok)
-    {
-      Contract.Requires(tok != null);
-      Contract.Requires(thn != null);
-      Contract.Requires(elseIf == null || elseBlock == null);
-      this.Guard = guard;
-      this._thn = thn;
-      this._elseIf = elseIf;
-      this._elseBlock = elseBlock;
-    }
-
-    public override void Emit(TokenTextWriter stream, int level)
-    {
-      stream.Write(level, "if (");
-      IfCmd /*!*/
-        ifcmd = this;
-      while (true)
-      {
-        if (ifcmd.Guard == null)
-        {
-          stream.Write("*");
-        }
-        else
-        {
-          ifcmd.Guard.Emit(stream);
-        }
-
-        stream.WriteLine(")");
-
-        stream.WriteLine(level, "{");
-        ifcmd.thn.Emit(stream, level + 1);
-        stream.WriteLine(level, "}");
-
-        if (ifcmd.elseIf != null)
-        {
-          stream.Write(level, "else if (");
-          ifcmd = ifcmd.elseIf;
-          continue;
-        }
-        else if (ifcmd.elseBlock != null)
-        {
-          stream.WriteLine(level, "else");
-          stream.WriteLine(level, "{");
-          ifcmd.elseBlock.Emit(stream, level + 1);
-          stream.WriteLine(level, "}");
-        }
-
-        break;
-      }
-    }
-  }
-
-  public class WhileCmd : StructuredCmd
-  {
-    [Peer] public Expr Guard;
-
-    public List<PredicateCmd> Invariants;
-
-    public List<CallCmd> Yields;
-
-    public StmtList Body;
-
-    [ContractInvariantMethod]
-    void ObjectInvariant()
-    {
-      Contract.Invariant(Body != null);
-      Contract.Invariant(cce.NonNullElements(Invariants));
-    }
-
-    public WhileCmd(IToken tok, [Captured] Expr guard, List<PredicateCmd> invariants, List<CallCmd> yields, StmtList body)
-      : base(tok)
-    {
-      Contract.Requires(cce.NonNullElements(invariants));
-      Contract.Requires(body != null);
-      Contract.Requires(tok != null);
-      this.Guard = guard;
-      this.Invariants = invariants;
-      this.Yields = yields;
-      this.Body = body;
-    }
-
-    public override void Emit(TokenTextWriter stream, int level)
-    {
-      stream.Write(level, "while (");
-      if (Guard == null)
-      {
-        stream.Write("*");
-      }
-      else
-      {
-        Guard.Emit(stream);
-      }
-
-      stream.WriteLine(")");
-
-      foreach (var yield in Yields)
-      {
-        stream.Write(level + 1, "invariant");
-        yield.Emit(stream, level + 1);
-      }
-      foreach (var inv in Invariants)
-      {
-        if (inv is AssumeCmd)
-        {
-          stream.Write(level + 1, "free invariant ");
-        }
-        else
-        {
-          stream.Write(level + 1, "invariant ");
-        }
-
-        Cmd.EmitAttributes(stream, inv.Attributes);
-        inv.Expr.Emit(stream);
-        stream.WriteLine(";");
-      }
-
-      stream.WriteLine(level, "{");
-      Body.Emit(stream, level + 1);
-      stream.WriteLine(level, "}");
-    }
-  }
-
   public class BreakCmd : StructuredCmd
   {
     public string Label;
diff --git a/Source/Core/AST/BigBlocksResolutionContext.cs b/Source/Core/AST/BigBlocksResolutionContext.cs
new file mode 100644
index 000000000..9d7a20fd5
--- /dev/null
+++ b/Source/Core/AST/BigBlocksResolutionContext.cs
@@ -0,0 +1,591 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+using System.Linq;
+
+namespace Microsoft.Boogie;
+
+class BigBlocksResolutionContext
+{
+  StmtList /*!*/ stmtList;
+
+  [Peer] List<Block /*!*/> blocks;
+
+  string /*!*/
+    prefix = "anon";
+
+  int anon = 0;
+
+  int FreshAnon()
+  {
+    return anon++;
+  }
+
+  HashSet<string /*!*/> allLabels = new HashSet<string /*!*/>();
+
+  Errors /*!*/
+    errorHandler;
+
+  [ContractInvariantMethod]
+  void ObjectInvariant()
+  {
+    Contract.Invariant(stmtList != null);
+    Contract.Invariant(cce.NonNullElements(blocks, true));
+    Contract.Invariant(prefix != null);
+    Contract.Invariant(cce.NonNullElements(allLabels, true));
+    Contract.Invariant(errorHandler != null);
+  }
+
+  private void ComputeAllLabels(StmtList stmts)
+  {
+    if (stmts == null)
+    {
+      return;
+    }
+
+    foreach (BigBlock bb in stmts.BigBlocks)
+    {
+      if (bb.LabelName != null)
+      {
+        allLabels.Add(bb.LabelName);
+      }
+
+      ComputeAllLabels(bb.ec);
+    }
+  }
+
+  private void ComputeAllLabels(StructuredCmd cmd)
+  {
+    if (cmd == null)
+    {
+      return;
+    }
+
+    if (cmd is IfCmd)
+    {
+      IfCmd ifCmd = (IfCmd) cmd;
+      ComputeAllLabels(ifCmd.thn);
+      ComputeAllLabels(ifCmd.elseIf);
+      ComputeAllLabels(ifCmd.elseBlock);
+    }
+    else if (cmd is WhileCmd)
+    {
+      WhileCmd whileCmd = (WhileCmd) cmd;
+      ComputeAllLabels(whileCmd.Body);
+    }
+  }
+
+  public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
+  {
+    Contract.Requires(errorHandler != null);
+    Contract.Requires(stmtList != null);
+    this.stmtList = stmtList;
+    // Inject an empty big block at the end of the body of a while loop if its current end is another while loop.
+    // This transformation creates a suitable jump target for break statements inside the nested while loop.
+    InjectEmptyBigBlockInsideWhileLoopBody(stmtList);
+    this.errorHandler = errorHandler;
+    ComputeAllLabels(stmtList);
+  }
+
+  public List<Block /*!*/> /*!*/ Blocks
+  {
+    get
+    {
+      Contract.Ensures(cce.NonNullElements(Contract.Result<List<Block>>()));
+      if (blocks == null)
+      {
+        blocks = new List<Block /*!*/>();
+
+        int startErrorCount = this.errorHandler.count;
+        // Check that all goto statements go to a label in allLabels, and no break statement to a non-enclosing loop.
+        // Also, determine a good value for "prefix".
+        CheckLegalLabels(stmtList, null, null);
+
+        // fill in names of anonymous blocks
+        NameAnonymousBlocks(stmtList);
+
+        // determine successor blocks
+        RecordSuccessors(stmtList, null);
+
+        if (this.errorHandler.count == startErrorCount)
+        {
+          // generate blocks from the big blocks
+          CreateBlocks(stmtList, null);
+        }
+      }
+
+      return blocks;
+    }
+  }
+
+  void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
+  {
+    foreach (var bb in stmtList.BigBlocks)
+    {
+      InjectEmptyBigBlockInsideWhileLoopBody(bb.ec);
+    }
+  }
+
+  void InjectEmptyBigBlockInsideWhileLoopBody(StructuredCmd structuredCmd)
+  {
+    if (structuredCmd is WhileCmd whileCmd)
+    {
+      InjectEmptyBigBlockInsideWhileLoopBody(whileCmd.Body);
+      if (whileCmd.Body.BigBlocks.Count > 0 && whileCmd.Body.BigBlocks.Last().ec is WhileCmd)
+      {
+        var newBigBlocks = new List<BigBlock>(whileCmd.Body.BigBlocks);
+        newBigBlocks.Add(new BigBlock(Token.NoToken, null, new List<Cmd>(), null, null));
+        whileCmd.Body = new StmtList(newBigBlocks, whileCmd.Body.EndCurly);
+      }
+    }
+    else if (structuredCmd is IfCmd ifCmd)
+    {
+      InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.thn);
+      if (ifCmd.elseBlock != null)
+      {
+        InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseBlock);
+      }
+
+      if (ifCmd.elseIf != null)
+      {
+        InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseIf);
+      }
+    }
+  }
+
+  void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
+  {
+    Contract.Requires(stmtList != null);
+    Contract.Requires((parentContext == null) == (parentBigBlock == null));
+    Contract.Requires(stmtList.ParentContext == null); // it hasn't been set yet
+    //modifies stmtList.*;
+    Contract.Ensures(stmtList.ParentContext == parentContext);
+    stmtList.ParentContext = parentContext;
+    stmtList.ParentBigBlock = parentBigBlock;
+
+    // record the labels declared in this StmtList
+    foreach (BigBlock b in stmtList.BigBlocks)
+    {
+      if (b.LabelName != null)
+      {
+        string n = b.LabelName;
+        if (n.StartsWith(prefix))
+        {
+          if (prefix.Length < n.Length && n[prefix.Length] == '0')
+          {
+            prefix += "1";
+          }
+          else
+          {
+            prefix += "0";
+          }
+        }
+
+        stmtList.AddLabel(b.LabelName);
+      }
+    }
+
+    // check that labels in this and nested StmtList's are legal
+    foreach (BigBlock b in stmtList.BigBlocks)
+    {
+      // goto's must reference blocks in enclosing blocks
+      if (b.tc is GotoCmd)
+      {
+        GotoCmd g = (GotoCmd) b.tc;
+        foreach (string /*!*/ lbl in cce.NonNull(g.labelNames))
+        {
+          Contract.Assert(lbl != null);
+          /*
+            bool found = false;
+            for (StmtList sl = stmtList; sl != null; sl = sl.ParentContext) {
+              if (sl.Labels.Contains(lbl)) {
+                found = true;
+                break;
+              }
+            }
+            if (!found) {
+              this.errorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined or out of reach");
+            }
+            */
+          if (!allLabels.Contains(lbl))
+          {
+            this.errorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined");
+          }
+        }
+      }
+
+      // break labels must refer to an enclosing while statement
+      else if (b.ec is BreakCmd)
+      {
+        BreakCmd bcmd = (BreakCmd) b.ec;
+        Contract.Assert(bcmd.BreakEnclosure == null); // it hasn't been initialized yet
+        bool found = false;
+        for (StmtList sl = stmtList; sl.ParentBigBlock != null; sl = sl.ParentContext)
+        {
+          cce.LoopInvariant(sl != null);
+          BigBlock bb = sl.ParentBigBlock;
+
+          if (bcmd.Label == null)
+          {
+            // a label-less break statement breaks out of the innermost enclosing while statement
+            if (bb.ec is WhileCmd)
+            {
+              bcmd.BreakEnclosure = bb;
+              found = true;
+              break;
+            }
+          }
+          else if (bcmd.Label == bb.LabelName)
+          {
+            // a break statement with a label can break out of both if statements and while statements
+            if (bb.simpleCmds.Count == 0)
+            {
+              // this is a good target:  the label refers to the if/while statement
+              bcmd.BreakEnclosure = bb;
+            }
+            else
+            {
+              // the label of bb refers to the first statement of bb, which in which case is a simple statement, not an if/while statement
+              this.errorHandler.SemErr(bcmd.tok,
+                "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
+            }
+
+            found = true; // don't look any further, since we've found a matching label
+            break;
+          }
+        }
+
+        if (!found)
+        {
+          if (bcmd.Label == null)
+          {
+            this.errorHandler.SemErr(bcmd.tok, "Error: break statement is not inside a loop");
+          }
+          else
+          {
+            this.errorHandler.SemErr(bcmd.tok,
+              "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
+          }
+        }
+      }
+
+      // recurse
+      else if (b.ec is WhileCmd)
+      {
+        WhileCmd wcmd = (WhileCmd) b.ec;
+        CheckLegalLabels(wcmd.Body, stmtList, b);
+      }
+      else
+      {
+        for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
+        {
+          CheckLegalLabels(ifcmd.thn, stmtList, b);
+          if (ifcmd.elseBlock != null)
+          {
+            CheckLegalLabels(ifcmd.elseBlock, stmtList, b);
+          }
+        }
+      }
+    }
+  }
+
+  void NameAnonymousBlocks(StmtList stmtList)
+  {
+    Contract.Requires(stmtList != null);
+    foreach (BigBlock b in stmtList.BigBlocks)
+    {
+      if (b.LabelName == null)
+      {
+        b.LabelName = prefix + FreshAnon();
+      }
+
+      if (b.ec is WhileCmd)
+      {
+        WhileCmd wcmd = (WhileCmd) b.ec;
+        NameAnonymousBlocks(wcmd.Body);
+      }
+      else
+      {
+        for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
+        {
+          NameAnonymousBlocks(ifcmd.thn);
+          if (ifcmd.elseBlock != null)
+          {
+            NameAnonymousBlocks(ifcmd.elseBlock);
+          }
+        }
+      }
+    }
+  }
+
+  void RecordSuccessors(StmtList stmtList, BigBlock successor)
+  {
+    Contract.Requires(stmtList != null);
+    for (int i = stmtList.BigBlocks.Count; 0 <= --i;)
+    {
+      BigBlock big = stmtList.BigBlocks[i];
+      big.successorBigBlock = successor;
+
+      if (big.ec is WhileCmd)
+      {
+        WhileCmd wcmd = (WhileCmd) big.ec;
+        RecordSuccessors(wcmd.Body, big);
+      }
+      else
+      {
+        for (IfCmd ifcmd = big.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
+        {
+          RecordSuccessors(ifcmd.thn, successor);
+          if (ifcmd.elseBlock != null)
+          {
+            RecordSuccessors(ifcmd.elseBlock, successor);
+          }
+        }
+      }
+
+      successor = big;
+    }
+  }
+
+  // If the enclosing context is a loop, then "runOffTheEndLabel" is the loop head label;
+  // otherwise, it is null.
+  void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
+  {
+    Contract.Requires(stmtList != null);
+    Contract.Requires(blocks != null);
+    List<Cmd> cmdPrefixToApply = stmtList.PrefixCommands;
+
+    int n = stmtList.BigBlocks.Count;
+    foreach (BigBlock b in stmtList.BigBlocks)
+    {
+      n--;
+      Contract.Assert(b.LabelName != null);
+      List<Cmd> theSimpleCmds;
+      if (cmdPrefixToApply == null)
+      {
+        theSimpleCmds = b.simpleCmds;
+      }
+      else
+      {
+        theSimpleCmds = new List<Cmd>();
+        theSimpleCmds.AddRange(cmdPrefixToApply);
+        theSimpleCmds.AddRange(b.simpleCmds);
+        cmdPrefixToApply = null; // now, we've used 'em up
+      }
+
+      if (b.tc != null)
+      {
+        // this BigBlock has the very same components as a Block
+        Contract.Assert(b.ec == null);
+        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, b.tc);
+        blocks.Add(block);
+      }
+      else if (b.ec == null)
+      {
+        TransferCmd trCmd;
+        if (n == 0 && runOffTheEndLabel != null)
+        {
+          // goto the given label instead of the textual successor block
+          trCmd = new GotoCmd(stmtList.EndCurly, new List<String> {runOffTheEndLabel});
+        }
+        else
+        {
+          trCmd = GotoSuccessor(stmtList.EndCurly, b);
+        }
+
+        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, trCmd);
+        blocks.Add(block);
+      }
+      else if (b.ec is BreakCmd)
+      {
+        BreakCmd bcmd = (BreakCmd) b.ec;
+        Contract.Assert(bcmd.BreakEnclosure != null);
+        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, GotoSuccessor(b.ec.tok, bcmd.BreakEnclosure));
+        blocks.Add(block);
+      }
+      else if (b.ec is WhileCmd)
+      {
+        WhileCmd wcmd = (WhileCmd) b.ec;
+        var a = FreshAnon();
+        string loopHeadLabel = prefix + a + "_LoopHead";
+        string /*!*/
+          loopBodyLabel = prefix + a + "_LoopBody";
+        string loopDoneLabel = prefix + a + "_LoopDone";
+
+        List<Cmd> ssBody = new List<Cmd>();
+        List<Cmd> ssDone = new List<Cmd>();
+        if (wcmd.Guard != null)
+        {
+          var ac = new AssumeCmd(wcmd.tok, wcmd.Guard);
+          ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
+          ssBody.Add(ac);
+
+          ac = new AssumeCmd(wcmd.tok, Expr.Not(wcmd.Guard));
+          ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
+          ssDone.Add(ac);
+        }
+
+        // Try to squeeze in ssBody into the first block of wcmd.Body
+        bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
+
+        // ... goto LoopHead;
+        Block block = new Block(b.tok, b.LabelName, theSimpleCmds,
+          new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
+        blocks.Add(block);
+
+        // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
+        List<Cmd> ssHead = new List<Cmd>();
+        foreach (CallCmd yield in wcmd.Yields)
+        {
+          ssHead.Add(yield);
+        }
+        foreach (PredicateCmd inv in wcmd.Invariants)
+        {
+          ssHead.Add(inv);
+        }
+
+        block = new Block(wcmd.tok, loopHeadLabel, ssHead,
+          new GotoCmd(wcmd.tok, new List<String> {loopDoneLabel, loopBodyLabel}));
+        blocks.Add(block);
+
+        if (!bodyGuardTakenCareOf)
+        {
+          // LoopBody: assume guard; goto firstLoopBlock;
+          block = new Block(wcmd.tok, loopBodyLabel, ssBody,
+            new GotoCmd(wcmd.tok, new List<String> {wcmd.Body.BigBlocks[0].LabelName}));
+          blocks.Add(block);
+        }
+
+        // recurse to create the blocks for the loop body
+        CreateBlocks(wcmd.Body, loopHeadLabel);
+
+        // LoopDone: assume !guard; goto loopSuccessor;
+        TransferCmd trCmd;
+        if (n == 0 && runOffTheEndLabel != null)
+        {
+          // goto the given label instead of the textual successor block
+          trCmd = new GotoCmd(wcmd.tok, new List<String> {runOffTheEndLabel});
+        }
+        else
+        {
+          trCmd = GotoSuccessor(wcmd.tok, b);
+        }
+
+        block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
+        blocks.Add(block);
+      }
+      else
+      {
+        IfCmd ifcmd = (IfCmd) b.ec;
+        string predLabel = b.LabelName;
+        List<Cmd> predCmds = theSimpleCmds;
+
+        for (; ifcmd != null; ifcmd = ifcmd.elseIf)
+        {
+          var a = FreshAnon();
+          string thenLabel = prefix + a + "_Then";
+          Contract.Assert(thenLabel != null);
+          string elseLabel = prefix + a + "_Else";
+          Contract.Assert(elseLabel != null);
+
+          List<Cmd> ssThen = new List<Cmd>();
+          List<Cmd> ssElse = new List<Cmd>();
+          if (ifcmd.Guard != null)
+          {
+            var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard);
+            ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+            ssThen.Add(ac);
+
+            ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
+            ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+            ssElse.Add(ac);
+          }
+
+          // Try to squeeze in ssThen/ssElse into the first block of ifcmd.thn/ifcmd.elseBlock
+          bool thenGuardTakenCareOf = ifcmd.thn.PrefixFirstBlock(ssThen, ref thenLabel);
+          bool elseGuardTakenCareOf = false;
+          if (ifcmd.elseBlock != null)
+          {
+            elseGuardTakenCareOf = ifcmd.elseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
+          }
+
+          // ... goto Then, Else;
+          var jumpBlock = new Block(b.tok, predLabel, predCmds,
+            new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
+          blocks.Add(jumpBlock);
+
+          if (!thenGuardTakenCareOf)
+          {
+            // Then: assume guard; goto firstThenBlock;
+            var thenJumpBlock = new Block(ifcmd.tok, thenLabel, ssThen,
+              new GotoCmd(ifcmd.tok, new List<String> {ifcmd.thn.BigBlocks[0].LabelName}));
+            blocks.Add(thenJumpBlock);
+          }
+
+          // recurse to create the blocks for the then branch
+          CreateBlocks(ifcmd.thn, n == 0 ? runOffTheEndLabel : null);
+
+          if (ifcmd.elseBlock != null)
+          {
+            Contract.Assert(ifcmd.elseIf == null);
+            if (!elseGuardTakenCareOf)
+            {
+              // Else: assume !guard; goto firstElseBlock;
+              var elseJumpBlock = new Block(ifcmd.tok, elseLabel, ssElse,
+                new GotoCmd(ifcmd.tok, new List<String> {ifcmd.elseBlock.BigBlocks[0].LabelName}));
+              blocks.Add(elseJumpBlock);
+            }
+
+            // recurse to create the blocks for the else branch
+            CreateBlocks(ifcmd.elseBlock, n == 0 ? runOffTheEndLabel : null);
+          }
+          else if (ifcmd.elseIf != null)
+          {
+            // this is an "else if"
+            predLabel = elseLabel;
+            predCmds = new List<Cmd>();
+            if (ifcmd.Guard != null)
+            {
+              var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
+              ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+              predCmds.Add(ac);
+            }
+          }
+          else
+          {
+            // no else alternative is specified, so else branch is just "skip"
+            // Else: assume !guard; goto ifSuccessor;
+            TransferCmd trCmd;
+            if (n == 0 && runOffTheEndLabel != null)
+            {
+              // goto the given label instead of the textual successor block
+              trCmd = new GotoCmd(ifcmd.tok, new List<String> {runOffTheEndLabel});
+            }
+            else
+            {
+              trCmd = GotoSuccessor(ifcmd.tok, b);
+            }
+
+            var block = new Block(ifcmd.tok, elseLabel, ssElse, trCmd);
+            blocks.Add(block);
+          }
+        }
+      }
+    }
+  }
+
+  TransferCmd GotoSuccessor(IToken tok, BigBlock b)
+  {
+    Contract.Requires(b != null);
+    Contract.Requires(tok != null);
+    Contract.Ensures(Contract.Result<TransferCmd>() != null);
+    if (b.successorBigBlock != null)
+    {
+      return new GotoCmd(tok, new List<String> {b.successorBigBlock.LabelName});
+    }
+    else
+    {
+      return new ReturnCmd(tok);
+    }
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/ByProofCmd.cs b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
new file mode 100644
index 000000000..d899b8c71
--- /dev/null
+++ b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
@@ -0,0 +1,16 @@
+namespace Microsoft.Boogie;
+
+public class ByProofCmd : StructuredCmd
+{
+  public StmtList Body;
+  public StmtList Proof;
+  
+  public ByProofCmd(IToken tok) : base(tok)
+  {
+  }
+
+  public override void Emit(TokenTextWriter stream, int level)
+  {
+    throw new System.NotImplementedException();
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/IfCmd.cs b/Source/Core/AST/StructuredCommands/IfCmd.cs
new file mode 100644
index 000000000..5f29f407d
--- /dev/null
+++ b/Source/Core/AST/StructuredCommands/IfCmd.cs
@@ -0,0 +1,108 @@
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Boogie;
+
+public class IfCmd : StructuredCmd
+{
+  public Expr Guard;
+
+  private StmtList /*!*/
+    _thn;
+
+  public StmtList /*!*/ thn
+  {
+    get
+    {
+      Contract.Ensures(Contract.Result<StmtList>() != null);
+      return this._thn;
+    }
+    set
+    {
+      Contract.Requires(value != null);
+      this._thn = value;
+    }
+  }
+
+  private IfCmd _elseIf;
+
+  public IfCmd elseIf
+  {
+    get { return this._elseIf; }
+    set
+    {
+      Contract.Requires(value == null || this.elseBlock == null);
+      this._elseIf = value;
+    }
+  }
+
+  private StmtList _elseBlock;
+
+  public StmtList elseBlock
+  {
+    get { return this._elseBlock; }
+    set
+    {
+      Contract.Requires(value == null || this.elseIf == null);
+      this._elseBlock = value;
+    }
+  }
+
+  [ContractInvariantMethod]
+  void ObjectInvariant()
+  {
+    Contract.Invariant(this._thn != null);
+    Contract.Invariant(this._elseIf == null || this._elseBlock == null);
+  }
+
+  public IfCmd(IToken /*!*/ tok, Expr guard, StmtList /*!*/ thn, IfCmd elseIf, StmtList elseBlock)
+    : base(tok)
+  {
+    Contract.Requires(tok != null);
+    Contract.Requires(thn != null);
+    Contract.Requires(elseIf == null || elseBlock == null);
+    this.Guard = guard;
+    this._thn = thn;
+    this._elseIf = elseIf;
+    this._elseBlock = elseBlock;
+  }
+
+  public override void Emit(TokenTextWriter stream, int level)
+  {
+    stream.Write(level, "if (");
+    IfCmd /*!*/
+      ifcmd = this;
+    while (true)
+    {
+      if (ifcmd.Guard == null)
+      {
+        stream.Write("*");
+      }
+      else
+      {
+        ifcmd.Guard.Emit(stream);
+      }
+
+      stream.WriteLine(")");
+
+      stream.WriteLine(level, "{");
+      ifcmd.thn.Emit(stream, level + 1);
+      stream.WriteLine(level, "}");
+
+      if (ifcmd.elseIf != null)
+      {
+        stream.Write(level, "else if (");
+        ifcmd = ifcmd.elseIf;
+        continue;
+      }
+      else if (ifcmd.elseBlock != null)
+      {
+        stream.WriteLine(level, "else");
+        stream.WriteLine(level, "{");
+        ifcmd.elseBlock.Emit(stream, level + 1);
+        stream.WriteLine(level, "}");
+      }
+
+      break;
+    }
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/WhileCmd.cs b/Source/Core/AST/StructuredCommands/WhileCmd.cs
new file mode 100644
index 000000000..135bd43ae
--- /dev/null
+++ b/Source/Core/AST/StructuredCommands/WhileCmd.cs
@@ -0,0 +1,74 @@
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Boogie;
+
+public class WhileCmd : StructuredCmd
+{
+  [Peer] public Expr Guard;
+
+  public List<PredicateCmd> Invariants;
+
+  public List<CallCmd> Yields;
+
+  public StmtList Body;
+
+  [ContractInvariantMethod]
+  void ObjectInvariant()
+  {
+    Contract.Invariant(Body != null);
+    Contract.Invariant(cce.NonNullElements(Invariants));
+  }
+
+  public WhileCmd(IToken tok, [Captured] Expr guard, List<PredicateCmd> invariants, List<CallCmd> yields, StmtList body)
+    : base(tok)
+  {
+    Contract.Requires(cce.NonNullElements(invariants));
+    Contract.Requires(body != null);
+    Contract.Requires(tok != null);
+    this.Guard = guard;
+    this.Invariants = invariants;
+    this.Yields = yields;
+    this.Body = body;
+  }
+
+  public override void Emit(TokenTextWriter stream, int level)
+  {
+    stream.Write(level, "while (");
+    if (Guard == null)
+    {
+      stream.Write("*");
+    }
+    else
+    {
+      Guard.Emit(stream);
+    }
+
+    stream.WriteLine(")");
+
+    foreach (var yield in Yields)
+    {
+      stream.Write(level + 1, "invariant");
+      yield.Emit(stream, level + 1);
+    }
+    foreach (var inv in Invariants)
+    {
+      if (inv is AssumeCmd)
+      {
+        stream.Write(level + 1, "free invariant ");
+      }
+      else
+      {
+        stream.Write(level + 1, "invariant ");
+      }
+
+      Cmd.EmitAttributes(stream, inv.Attributes);
+      inv.Expr.Emit(stream);
+      stream.WriteLine(";");
+    }
+
+    stream.WriteLine(level, "{");
+    Body.Emit(stream, level + 1);
+    stream.WriteLine(level, "}");
+  }
+}
\ No newline at end of file

From 30ba83891fdc2ad65539bebaaaff27d88374931c Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 16 Sep 2024 14:40:31 +0200
Subject: [PATCH 4/9] Move some code into structured command sublcasses

---
 Source/Core/AST/AbsyCmd.cs                    |  60 ----
 Source/Core/AST/BigBlocksResolutionContext.cs | 332 ++----------------
 .../Core/AST/StructuredCommands/BreakCmd.cs   |  98 ++++++
 .../Core/AST/StructuredCommands/ByProofCmd.cs |  23 ++
 Source/Core/AST/StructuredCommands/IfCmd.cs   | 134 +++++++
 .../AST/StructuredCommands/StructuredCmd.cs   |  46 +++
 .../Core/AST/StructuredCommands/WhileCmd.cs   |  98 ++++++
 7 files changed, 427 insertions(+), 364 deletions(-)
 create mode 100644 Source/Core/AST/StructuredCommands/BreakCmd.cs
 create mode 100644 Source/Core/AST/StructuredCommands/StructuredCmd.cs

diff --git a/Source/Core/AST/AbsyCmd.cs b/Source/Core/AST/AbsyCmd.cs
index 24ace542c..408619a1f 100644
--- a/Source/Core/AST/AbsyCmd.cs
+++ b/Source/Core/AST/AbsyCmd.cs
@@ -351,41 +351,6 @@ public void AddLocalVariable(string name)
     }
   }
 
-  [ContractClass(typeof(StructuredCmdContracts))]
-  public abstract class StructuredCmd
-  {
-    private IToken /*!*/
-      _tok;
-
-    public IToken /*!*/ tok
-    {
-      get
-      {
-        Contract.Ensures(Contract.Result<IToken>() != null);
-        return this._tok;
-      }
-      set
-      {
-        Contract.Requires(value != null);
-        this._tok = value;
-      }
-    }
-
-    [ContractInvariantMethod]
-    void ObjectInvariant()
-    {
-      Contract.Invariant(this._tok != null);
-    }
-
-    public StructuredCmd(IToken tok)
-    {
-      Contract.Requires(tok != null);
-      this._tok = tok;
-    }
-
-    public abstract void Emit(TokenTextWriter /*!*/ stream, int level);
-  }
-
   [ContractClassFor(typeof(StructuredCmd))]
   public abstract class StructuredCmdContracts : StructuredCmd
   {
@@ -400,31 +365,6 @@ public StructuredCmdContracts() : base(null)
     }
   }
 
-  public class BreakCmd : StructuredCmd
-  {
-    public string Label;
-    public BigBlock BreakEnclosure;
-
-    public BreakCmd(IToken tok, string label)
-      : base(tok)
-    {
-      Contract.Requires(tok != null);
-      this.Label = label;
-    }
-
-    public override void Emit(TokenTextWriter stream, int level)
-    {
-      if (Label == null)
-      {
-        stream.WriteLine(level, "break;");
-      }
-      else
-      {
-        stream.WriteLine(level, "break {0};", Label);
-      }
-    }
-  }
-
   //---------------------------------------------------------------------
   // Block
 
diff --git a/Source/Core/AST/BigBlocksResolutionContext.cs b/Source/Core/AST/BigBlocksResolutionContext.cs
index 9d7a20fd5..3753558f2 100644
--- a/Source/Core/AST/BigBlocksResolutionContext.cs
+++ b/Source/Core/AST/BigBlocksResolutionContext.cs
@@ -1,30 +1,27 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
-using System.Linq;
 
 namespace Microsoft.Boogie;
 
-class BigBlocksResolutionContext
+public class BigBlocksResolutionContext
 {
   StmtList /*!*/ stmtList;
 
   [Peer] List<Block /*!*/> blocks;
 
-  string /*!*/
-    prefix = "anon";
+  string /*!*/ prefix = "anon";
 
   int anon = 0;
 
-  int FreshAnon()
+  public string FreshPrefix()
   {
-    return anon++;
+    return prefix + anon++;
   }
 
-  HashSet<string /*!*/> allLabels = new HashSet<string /*!*/>();
+  HashSet<string /*!*/> allLabels = new();
 
-  Errors /*!*/
-    errorHandler;
+  public Errors ErrorHandler { get; }
 
   [ContractInvariantMethod]
   void ObjectInvariant()
@@ -33,10 +30,10 @@ void ObjectInvariant()
     Contract.Invariant(cce.NonNullElements(blocks, true));
     Contract.Invariant(prefix != null);
     Contract.Invariant(cce.NonNullElements(allLabels, true));
-    Contract.Invariant(errorHandler != null);
+    Contract.Invariant(ErrorHandler != null);
   }
 
-  private void ComputeAllLabels(StmtList stmts)
+  public void ComputeAllLabels(StmtList stmts)
   {
     if (stmts == null)
     {
@@ -50,7 +47,7 @@ private void ComputeAllLabels(StmtList stmts)
         allLabels.Add(bb.LabelName);
       }
 
-      ComputeAllLabels(bb.ec);
+      bb.ec?.ComputeAllLabels(this);
     }
   }
 
@@ -60,19 +57,8 @@ private void ComputeAllLabels(StructuredCmd cmd)
     {
       return;
     }
-
-    if (cmd is IfCmd)
-    {
-      IfCmd ifCmd = (IfCmd) cmd;
-      ComputeAllLabels(ifCmd.thn);
-      ComputeAllLabels(ifCmd.elseIf);
-      ComputeAllLabels(ifCmd.elseBlock);
-    }
-    else if (cmd is WhileCmd)
-    {
-      WhileCmd whileCmd = (WhileCmd) cmd;
-      ComputeAllLabels(whileCmd.Body);
-    }
+    
+    cmd.ComputeAllLabels(this);
   }
 
   public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
@@ -83,10 +69,15 @@ public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
     // Inject an empty big block at the end of the body of a while loop if its current end is another while loop.
     // This transformation creates a suitable jump target for break statements inside the nested while loop.
     InjectEmptyBigBlockInsideWhileLoopBody(stmtList);
-    this.errorHandler = errorHandler;
+    this.ErrorHandler = errorHandler;
     ComputeAllLabels(stmtList);
   }
 
+  public void AddBlock(Block block)
+  {
+    blocks.Add(block);
+  }
+
   public List<Block /*!*/> /*!*/ Blocks
   {
     get
@@ -96,7 +87,7 @@ public List<Block /*!*/> /*!*/ Blocks
       {
         blocks = new List<Block /*!*/>();
 
-        int startErrorCount = this.errorHandler.count;
+        int startErrorCount = this.ErrorHandler.count;
         // Check that all goto statements go to a label in allLabels, and no break statement to a non-enclosing loop.
         // Also, determine a good value for "prefix".
         CheckLegalLabels(stmtList, null, null);
@@ -107,7 +98,7 @@ public List<Block /*!*/> /*!*/ Blocks
         // determine successor blocks
         RecordSuccessors(stmtList, null);
 
-        if (this.errorHandler.count == startErrorCount)
+        if (this.ErrorHandler.count == startErrorCount)
         {
           // generate blocks from the big blocks
           CreateBlocks(stmtList, null);
@@ -118,42 +109,15 @@ public List<Block /*!*/> /*!*/ Blocks
     }
   }
 
-  void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
+  public void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
   {
     foreach (var bb in stmtList.BigBlocks)
     {
-      InjectEmptyBigBlockInsideWhileLoopBody(bb.ec);
-    }
-  }
-
-  void InjectEmptyBigBlockInsideWhileLoopBody(StructuredCmd structuredCmd)
-  {
-    if (structuredCmd is WhileCmd whileCmd)
-    {
-      InjectEmptyBigBlockInsideWhileLoopBody(whileCmd.Body);
-      if (whileCmd.Body.BigBlocks.Count > 0 && whileCmd.Body.BigBlocks.Last().ec is WhileCmd)
-      {
-        var newBigBlocks = new List<BigBlock>(whileCmd.Body.BigBlocks);
-        newBigBlocks.Add(new BigBlock(Token.NoToken, null, new List<Cmd>(), null, null));
-        whileCmd.Body = new StmtList(newBigBlocks, whileCmd.Body.EndCurly);
-      }
-    }
-    else if (structuredCmd is IfCmd ifCmd)
-    {
-      InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.thn);
-      if (ifCmd.elseBlock != null)
-      {
-        InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseBlock);
-      }
-
-      if (ifCmd.elseIf != null)
-      {
-        InjectEmptyBigBlockInsideWhileLoopBody(ifCmd.elseIf);
-      }
+      bb.ec.InjectEmptyBigBlockInsideWhileLoopBody(this);
     }
   }
 
-  void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
+  public void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
   {
     Contract.Requires(stmtList != null);
     Contract.Requires((parentContext == null) == (parentBigBlock == null));
@@ -209,82 +173,13 @@ void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parent
             */
           if (!allLabels.Contains(lbl))
           {
-            this.errorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined");
+            this.ErrorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined");
           }
         }
       }
-
-      // break labels must refer to an enclosing while statement
-      else if (b.ec is BreakCmd)
-      {
-        BreakCmd bcmd = (BreakCmd) b.ec;
-        Contract.Assert(bcmd.BreakEnclosure == null); // it hasn't been initialized yet
-        bool found = false;
-        for (StmtList sl = stmtList; sl.ParentBigBlock != null; sl = sl.ParentContext)
-        {
-          cce.LoopInvariant(sl != null);
-          BigBlock bb = sl.ParentBigBlock;
-
-          if (bcmd.Label == null)
-          {
-            // a label-less break statement breaks out of the innermost enclosing while statement
-            if (bb.ec is WhileCmd)
-            {
-              bcmd.BreakEnclosure = bb;
-              found = true;
-              break;
-            }
-          }
-          else if (bcmd.Label == bb.LabelName)
-          {
-            // a break statement with a label can break out of both if statements and while statements
-            if (bb.simpleCmds.Count == 0)
-            {
-              // this is a good target:  the label refers to the if/while statement
-              bcmd.BreakEnclosure = bb;
-            }
-            else
-            {
-              // the label of bb refers to the first statement of bb, which in which case is a simple statement, not an if/while statement
-              this.errorHandler.SemErr(bcmd.tok,
-                "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
-            }
-
-            found = true; // don't look any further, since we've found a matching label
-            break;
-          }
-        }
-
-        if (!found)
-        {
-          if (bcmd.Label == null)
-          {
-            this.errorHandler.SemErr(bcmd.tok, "Error: break statement is not inside a loop");
-          }
-          else
-          {
-            this.errorHandler.SemErr(bcmd.tok,
-              "Error: break label '" + bcmd.Label + "' must designate an enclosing statement");
-          }
-        }
-      }
-
-      // recurse
-      else if (b.ec is WhileCmd)
-      {
-        WhileCmd wcmd = (WhileCmd) b.ec;
-        CheckLegalLabels(wcmd.Body, stmtList, b);
-      }
       else
       {
-        for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-        {
-          CheckLegalLabels(ifcmd.thn, stmtList, b);
-          if (ifcmd.elseBlock != null)
-          {
-            CheckLegalLabels(ifcmd.elseBlock, stmtList, b);
-          }
-        }
+        b.ec.CheckLegalLabels(this, this.stmtList, b);
       }
     }
   }
@@ -296,7 +191,7 @@ void NameAnonymousBlocks(StmtList stmtList)
     {
       if (b.LabelName == null)
       {
-        b.LabelName = prefix + FreshAnon();
+        b.LabelName = FreshPrefix();
       }
 
       if (b.ec is WhileCmd)
@@ -349,7 +244,7 @@ void RecordSuccessors(StmtList stmtList, BigBlock successor)
 
   // If the enclosing context is a loop, then "runOffTheEndLabel" is the loop head label;
   // otherwise, it is null.
-  void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
+  public void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
   {
     Contract.Requires(stmtList != null);
     Contract.Requires(blocks != null);
@@ -396,185 +291,14 @@ void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
         Block block = new Block(b.tok, b.LabelName, theSimpleCmds, trCmd);
         blocks.Add(block);
       }
-      else if (b.ec is BreakCmd)
-      {
-        BreakCmd bcmd = (BreakCmd) b.ec;
-        Contract.Assert(bcmd.BreakEnclosure != null);
-        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, GotoSuccessor(b.ec.tok, bcmd.BreakEnclosure));
-        blocks.Add(block);
-      }
-      else if (b.ec is WhileCmd)
-      {
-        WhileCmd wcmd = (WhileCmd) b.ec;
-        var a = FreshAnon();
-        string loopHeadLabel = prefix + a + "_LoopHead";
-        string /*!*/
-          loopBodyLabel = prefix + a + "_LoopBody";
-        string loopDoneLabel = prefix + a + "_LoopDone";
-
-        List<Cmd> ssBody = new List<Cmd>();
-        List<Cmd> ssDone = new List<Cmd>();
-        if (wcmd.Guard != null)
-        {
-          var ac = new AssumeCmd(wcmd.tok, wcmd.Guard);
-          ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-          ssBody.Add(ac);
-
-          ac = new AssumeCmd(wcmd.tok, Expr.Not(wcmd.Guard));
-          ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-          ssDone.Add(ac);
-        }
-
-        // Try to squeeze in ssBody into the first block of wcmd.Body
-        bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
-
-        // ... goto LoopHead;
-        Block block = new Block(b.tok, b.LabelName, theSimpleCmds,
-          new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
-        blocks.Add(block);
-
-        // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
-        List<Cmd> ssHead = new List<Cmd>();
-        foreach (CallCmd yield in wcmd.Yields)
-        {
-          ssHead.Add(yield);
-        }
-        foreach (PredicateCmd inv in wcmd.Invariants)
-        {
-          ssHead.Add(inv);
-        }
-
-        block = new Block(wcmd.tok, loopHeadLabel, ssHead,
-          new GotoCmd(wcmd.tok, new List<String> {loopDoneLabel, loopBodyLabel}));
-        blocks.Add(block);
-
-        if (!bodyGuardTakenCareOf)
-        {
-          // LoopBody: assume guard; goto firstLoopBlock;
-          block = new Block(wcmd.tok, loopBodyLabel, ssBody,
-            new GotoCmd(wcmd.tok, new List<String> {wcmd.Body.BigBlocks[0].LabelName}));
-          blocks.Add(block);
-        }
-
-        // recurse to create the blocks for the loop body
-        CreateBlocks(wcmd.Body, loopHeadLabel);
-
-        // LoopDone: assume !guard; goto loopSuccessor;
-        TransferCmd trCmd;
-        if (n == 0 && runOffTheEndLabel != null)
-        {
-          // goto the given label instead of the textual successor block
-          trCmd = new GotoCmd(wcmd.tok, new List<String> {runOffTheEndLabel});
-        }
-        else
-        {
-          trCmd = GotoSuccessor(wcmd.tok, b);
-        }
-
-        block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
-        blocks.Add(block);
-      }
       else
       {
-        IfCmd ifcmd = (IfCmd) b.ec;
-        string predLabel = b.LabelName;
-        List<Cmd> predCmds = theSimpleCmds;
-
-        for (; ifcmd != null; ifcmd = ifcmd.elseIf)
-        {
-          var a = FreshAnon();
-          string thenLabel = prefix + a + "_Then";
-          Contract.Assert(thenLabel != null);
-          string elseLabel = prefix + a + "_Else";
-          Contract.Assert(elseLabel != null);
-
-          List<Cmd> ssThen = new List<Cmd>();
-          List<Cmd> ssElse = new List<Cmd>();
-          if (ifcmd.Guard != null)
-          {
-            var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard);
-            ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-            ssThen.Add(ac);
-
-            ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-            ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-            ssElse.Add(ac);
-          }
-
-          // Try to squeeze in ssThen/ssElse into the first block of ifcmd.thn/ifcmd.elseBlock
-          bool thenGuardTakenCareOf = ifcmd.thn.PrefixFirstBlock(ssThen, ref thenLabel);
-          bool elseGuardTakenCareOf = false;
-          if (ifcmd.elseBlock != null)
-          {
-            elseGuardTakenCareOf = ifcmd.elseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
-          }
-
-          // ... goto Then, Else;
-          var jumpBlock = new Block(b.tok, predLabel, predCmds,
-            new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
-          blocks.Add(jumpBlock);
-
-          if (!thenGuardTakenCareOf)
-          {
-            // Then: assume guard; goto firstThenBlock;
-            var thenJumpBlock = new Block(ifcmd.tok, thenLabel, ssThen,
-              new GotoCmd(ifcmd.tok, new List<String> {ifcmd.thn.BigBlocks[0].LabelName}));
-            blocks.Add(thenJumpBlock);
-          }
-
-          // recurse to create the blocks for the then branch
-          CreateBlocks(ifcmd.thn, n == 0 ? runOffTheEndLabel : null);
-
-          if (ifcmd.elseBlock != null)
-          {
-            Contract.Assert(ifcmd.elseIf == null);
-            if (!elseGuardTakenCareOf)
-            {
-              // Else: assume !guard; goto firstElseBlock;
-              var elseJumpBlock = new Block(ifcmd.tok, elseLabel, ssElse,
-                new GotoCmd(ifcmd.tok, new List<String> {ifcmd.elseBlock.BigBlocks[0].LabelName}));
-              blocks.Add(elseJumpBlock);
-            }
-
-            // recurse to create the blocks for the else branch
-            CreateBlocks(ifcmd.elseBlock, n == 0 ? runOffTheEndLabel : null);
-          }
-          else if (ifcmd.elseIf != null)
-          {
-            // this is an "else if"
-            predLabel = elseLabel;
-            predCmds = new List<Cmd>();
-            if (ifcmd.Guard != null)
-            {
-              var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-              ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-              predCmds.Add(ac);
-            }
-          }
-          else
-          {
-            // no else alternative is specified, so else branch is just "skip"
-            // Else: assume !guard; goto ifSuccessor;
-            TransferCmd trCmd;
-            if (n == 0 && runOffTheEndLabel != null)
-            {
-              // goto the given label instead of the textual successor block
-              trCmd = new GotoCmd(ifcmd.tok, new List<String> {runOffTheEndLabel});
-            }
-            else
-            {
-              trCmd = GotoSuccessor(ifcmd.tok, b);
-            }
-
-            var block = new Block(ifcmd.tok, elseLabel, ssElse, trCmd);
-            blocks.Add(block);
-          }
-        }
+        b.ec.CreateBlocks(this, b, theSimpleCmds, stmtList, n == 0 ? runOffTheEndLabel : null);
       }
     }
   }
 
-  TransferCmd GotoSuccessor(IToken tok, BigBlock b)
+  public static TransferCmd GotoSuccessor(IToken tok, BigBlock b)
   {
     Contract.Requires(b != null);
     Contract.Requires(tok != null);
diff --git a/Source/Core/AST/StructuredCommands/BreakCmd.cs b/Source/Core/AST/StructuredCommands/BreakCmd.cs
new file mode 100644
index 000000000..158f8f466
--- /dev/null
+++ b/Source/Core/AST/StructuredCommands/BreakCmd.cs
@@ -0,0 +1,98 @@
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Boogie;
+
+public class BreakCmd : StructuredCmd
+{
+  public string Label;
+  public BigBlock BreakEnclosure;
+
+  public BreakCmd(IToken tok, string label)
+    : base(tok)
+  {
+    Contract.Requires(tok != null);
+    Label = label;
+  }
+
+  public override void Emit(TokenTextWriter stream, int level)
+  {
+    if (Label == null)
+    {
+      stream.WriteLine(level, "break;");
+    }
+    else
+    {
+      stream.WriteLine(level, "break {0};", Label);
+    }
+  }
+
+  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
+  {
+  }
+
+  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
+  {
+    Contract.Assert(BreakEnclosure == null); // it hasn't been initialized yet
+    bool found = false;
+    for (StmtList sl = stmtList; sl.ParentBigBlock != null; sl = sl.ParentContext)
+    {
+      cce.LoopInvariant(sl != null);
+      BigBlock bb = sl.ParentBigBlock;
+
+      if (Label == null)
+      {
+        // a label-less break statement breaks out of the innermost enclosing while statement
+        if (bb.ec is WhileCmd)
+        {
+          BreakEnclosure = bb;
+          found = true;
+          break;
+        }
+      }
+      else if (Label == bb.LabelName)
+      {
+        // a break statement with a label can break out of both if statements and while statements
+        if (bb.simpleCmds.Count == 0)
+        {
+          // this is a good target:  the label refers to the if/while statement
+          BreakEnclosure = bb;
+        }
+        else
+        {
+          // the label of bb refers to the first statement of bb, which in which case is a simple statement, not an if/while statement
+          context.ErrorHandler.SemErr(tok,
+            "Error: break label '" + Label + "' must designate an enclosing statement");
+        }
+
+        found = true; // don't look any further, since we've found a matching label
+        break;
+      }
+    }
+
+    if (!found)
+    {
+      if (Label == null)
+      {
+        context.ErrorHandler.SemErr(tok, "Error: break statement is not inside a loop");
+      }
+      else
+      {
+        context.ErrorHandler.SemErr(tok,
+          "Error: break label '" + Label + "' must designate an enclosing statement");
+      }
+    }
+  }
+
+  public override void ComputeAllLabels(BigBlocksResolutionContext context)
+  {
+  }
+
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
+    string runOffTheEndLabel)
+  {
+    Contract.Assert(this.BreakEnclosure != null);
+    Block block = new Block(b.tok, b.LabelName, theSimpleCmds, BigBlocksResolutionContext.GotoSuccessor(b.ec.tok, BreakEnclosure));
+    context.AddBlock(block);
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/ByProofCmd.cs b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
index d899b8c71..4fb49476c 100644
--- a/Source/Core/AST/StructuredCommands/ByProofCmd.cs
+++ b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+
 namespace Microsoft.Boogie;
 
 public class ByProofCmd : StructuredCmd
@@ -13,4 +15,25 @@ public override void Emit(TokenTextWriter stream, int level)
   {
     throw new System.NotImplementedException();
   }
+
+  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
+  {
+    throw new System.NotImplementedException();
+  }
+
+  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
+  {
+    throw new System.NotImplementedException();
+  }
+
+  public override void ComputeAllLabels(BigBlocksResolutionContext context)
+  {
+    throw new System.NotImplementedException();
+  }
+
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
+    string runOffTheEndLabel)
+  {
+    throw new System.NotImplementedException();
+  }
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/IfCmd.cs b/Source/Core/AST/StructuredCommands/IfCmd.cs
index 5f29f407d..bbac4e709 100644
--- a/Source/Core/AST/StructuredCommands/IfCmd.cs
+++ b/Source/Core/AST/StructuredCommands/IfCmd.cs
@@ -1,3 +1,5 @@
+using System;
+using System.Collections.Generic;
 using System.Diagnostics.Contracts;
 
 namespace Microsoft.Boogie;
@@ -105,4 +107,136 @@ public override void Emit(TokenTextWriter stream, int level)
       break;
     }
   }
+
+  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
+  {
+    context.InjectEmptyBigBlockInsideWhileLoopBody(thn);
+    if (elseBlock != null)
+    {
+      context.InjectEmptyBigBlockInsideWhileLoopBody(elseBlock);
+    }
+
+    if (elseIf != null)
+    {
+      elseIf.InjectEmptyBigBlockInsideWhileLoopBody(context);
+    }
+  }
+
+  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
+  {
+    for (IfCmd ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
+    {
+      context.CheckLegalLabels(ifcmd.thn, stmtList, bigBlock);
+      if (ifcmd.elseBlock != null)
+      {
+        context.CheckLegalLabels(ifcmd.elseBlock, stmtList, bigBlock);
+      }
+    }
+  }
+
+  public override void ComputeAllLabels(BigBlocksResolutionContext context)
+  {
+    context.ComputeAllLabels(thn);
+    elseIf.ComputeAllLabels(context);
+    context.ComputeAllLabels(elseBlock);
+  }
+
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
+    string runOffTheEndLabel)
+  {
+    IfCmd ifcmd = (IfCmd) b.ec;
+    string predLabel = b.LabelName;
+    List<Cmd> predCmds = theSimpleCmds;
+
+    for (; ifcmd != null; ifcmd = ifcmd.elseIf)
+    {
+      var prefix = context.FreshPrefix();
+      string thenLabel = prefix + "_Then";
+      Contract.Assert(thenLabel != null);
+      string elseLabel = prefix + "_Else";
+      Contract.Assert(elseLabel != null);
+
+      List<Cmd> ssThen = new List<Cmd>();
+      List<Cmd> ssElse = new List<Cmd>();
+      if (ifcmd.Guard != null)
+      {
+        var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard);
+        ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+        ssThen.Add(ac);
+
+        ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
+        ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+        ssElse.Add(ac);
+      }
+
+      // Try to squeeze in ssThen/ssElse into the first block of ifcmd.thn/ifcmd.elseBlock
+      bool thenGuardTakenCareOf = ifcmd.thn.PrefixFirstBlock(ssThen, ref thenLabel);
+      bool elseGuardTakenCareOf = false;
+      if (ifcmd.elseBlock != null)
+      {
+        elseGuardTakenCareOf = ifcmd.elseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
+      }
+
+      // ... goto Then, Else;
+      var jumpBlock = new Block(b.tok, predLabel, predCmds,
+        new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
+      context.AddBlock(jumpBlock);
+
+      if (!thenGuardTakenCareOf)
+      {
+        // Then: assume guard; goto firstThenBlock;
+        var thenJumpBlock = new Block(ifcmd.tok, thenLabel, ssThen,
+          new GotoCmd(ifcmd.tok, new List<String> {ifcmd.thn.BigBlocks[0].LabelName}));
+        context.AddBlock(thenJumpBlock);
+      }
+
+      // recurse to create the blocks for the then branch
+      context.CreateBlocks(ifcmd.thn, runOffTheEndLabel);
+
+      if (ifcmd.elseBlock != null)
+      {
+        Contract.Assert(ifcmd.elseIf == null);
+        if (!elseGuardTakenCareOf)
+        {
+          // Else: assume !guard; goto firstElseBlock;
+          var elseJumpBlock = new Block(ifcmd.tok, elseLabel, ssElse,
+            new GotoCmd(ifcmd.tok, new List<String> {ifcmd.elseBlock.BigBlocks[0].LabelName}));
+          context.AddBlock(elseJumpBlock);
+        }
+
+        // recurse to create the blocks for the else branch
+        context.CreateBlocks(ifcmd.elseBlock, runOffTheEndLabel);
+      }
+      else if (ifcmd.elseIf != null)
+      {
+        // this is an "else if"
+        predLabel = elseLabel;
+        predCmds = new List<Cmd>();
+        if (ifcmd.Guard != null)
+        {
+          var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
+          ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+          predCmds.Add(ac);
+        }
+      }
+      else
+      {
+        // no else alternative is specified, so else branch is just "skip"
+        // Else: assume !guard; goto ifSuccessor;
+        TransferCmd trCmd;
+        if (runOffTheEndLabel != null)
+        {
+          // goto the given label instead of the textual successor block
+          trCmd = new GotoCmd(ifcmd.tok, new List<String> {runOffTheEndLabel});
+        }
+        else
+        {
+          trCmd = BigBlocksResolutionContext.GotoSuccessor(ifcmd.tok, b);
+        }
+
+        var block = new Block(ifcmd.tok, elseLabel, ssElse, trCmd);
+        context.AddBlock(block);
+      }
+    }
+  }
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/StructuredCmd.cs b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
new file mode 100644
index 000000000..cdf993ea0
--- /dev/null
+++ b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Boogie;
+
+[ContractClass(typeof(StructuredCmdContracts))]
+public abstract class StructuredCmd
+{
+  private IToken /*!*/
+    _tok;
+
+  public IToken /*!*/ tok
+  {
+    get
+    {
+      Contract.Ensures(Contract.Result<IToken>() != null);
+      return this._tok;
+    }
+    set
+    {
+      Contract.Requires(value != null);
+      this._tok = value;
+    }
+  }
+
+  [ContractInvariantMethod]
+  void ObjectInvariant()
+  {
+    Contract.Invariant(this._tok != null);
+  }
+
+  public StructuredCmd(IToken tok)
+  {
+    Contract.Requires(tok != null);
+    this._tok = tok;
+  }
+
+  public abstract void Emit(TokenTextWriter /*!*/ stream, int level);
+
+  public abstract void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context);
+  public abstract void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock);
+  public abstract void ComputeAllLabels(BigBlocksResolutionContext context);
+  public abstract void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds,
+    StmtList stmtList,
+    string runOffTheEndLabel);
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/WhileCmd.cs b/Source/Core/AST/StructuredCommands/WhileCmd.cs
index 135bd43ae..99a99742e 100644
--- a/Source/Core/AST/StructuredCommands/WhileCmd.cs
+++ b/Source/Core/AST/StructuredCommands/WhileCmd.cs
@@ -1,5 +1,7 @@
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
+using System.Linq;
 
 namespace Microsoft.Boogie;
 
@@ -71,4 +73,100 @@ public override void Emit(TokenTextWriter stream, int level)
     Body.Emit(stream, level + 1);
     stream.WriteLine(level, "}");
   }
+
+  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
+  {
+    context.InjectEmptyBigBlockInsideWhileLoopBody(Body);
+    if (Body.BigBlocks.Count <= 0 || Body.BigBlocks.Last().ec is not WhileCmd)
+    {
+      return;
+    }
+
+    var newBigBlocks = new List<BigBlock>(Body.BigBlocks);
+    newBigBlocks.Add(new BigBlock(Token.NoToken, null, new List<Cmd>(), null, null));
+    Body = new StmtList(newBigBlocks, Body.EndCurly);
+  }
+
+  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
+  {
+    context.CheckLegalLabels(Body, stmtList, bigBlock);
+  }
+
+  public override void ComputeAllLabels(BigBlocksResolutionContext context)
+  {
+    context.ComputeAllLabels(Body);
+  }
+
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds,
+    StmtList stmtList,
+    string runOffTheEndLabel)
+  {
+      WhileCmd wcmd = (WhileCmd) this;
+      var prefix = context.FreshPrefix();
+      string loopHeadLabel = prefix + "_LoopHead";
+      string /*!*/ loopBodyLabel = prefix + "_LoopBody";
+      string loopDoneLabel = prefix + "_LoopDone";
+
+      List<Cmd> ssBody = new List<Cmd>();
+      List<Cmd> ssDone = new List<Cmd>();
+      if (wcmd.Guard != null)
+      {
+        var ac = new AssumeCmd(wcmd.tok, wcmd.Guard);
+        ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
+        ssBody.Add(ac);
+
+        ac = new AssumeCmd(wcmd.tok, Expr.Not(wcmd.Guard));
+        ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
+        ssDone.Add(ac);
+      }
+
+      // Try to squeeze in ssBody into the first block of wcmd.Body
+      bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
+
+      // ... goto LoopHead;
+      Block block = new Block(b.tok, b.LabelName, theSimpleCmds,
+        new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
+      context.AddBlock(block);
+
+      // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
+      List<Cmd> ssHead = new List<Cmd>();
+      foreach (CallCmd yield in wcmd.Yields)
+      {
+        ssHead.Add(yield);
+      }
+      foreach (PredicateCmd inv in wcmd.Invariants)
+      {
+        ssHead.Add(inv);
+      }
+
+      block = new Block(wcmd.tok, loopHeadLabel, ssHead,
+        new GotoCmd(wcmd.tok, new List<String> {loopDoneLabel, loopBodyLabel}));
+      context.AddBlock(block);
+
+      if (!bodyGuardTakenCareOf)
+      {
+        // LoopBody: assume guard; goto firstLoopBlock;
+        block = new Block(wcmd.tok, loopBodyLabel, ssBody,
+          new GotoCmd(wcmd.tok, new List<String> {wcmd.Body.BigBlocks[0].LabelName}));
+        context.AddBlock(block);
+      }
+
+      // recurse to create the blocks for the loop body
+      context.CreateBlocks(wcmd.Body, loopHeadLabel);
+
+      // LoopDone: assume !guard; goto loopSuccessor;
+      TransferCmd trCmd;
+      if (runOffTheEndLabel != null)
+      {
+        // goto the given label instead of the textual successor block
+        trCmd = new GotoCmd(wcmd.tok, new List<String> {runOffTheEndLabel});
+      }
+      else
+      {
+        trCmd = BigBlocksResolutionContext.GotoSuccessor(wcmd.tok, b);
+      }
+
+      block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
+      context.AddBlock(block);
+  }
 }
\ No newline at end of file

From f690907c9141edf8098f539d3bba3c9510a7c439 Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 16 Sep 2024 15:05:28 +0200
Subject: [PATCH 5/9] Further refactoring

---
 Source/Core/AST/BigBlocksResolutionContext.cs | 60 +++++--------------
 .../Core/AST/StructuredCommands/BreakCmd.cs   | 14 +++--
 .../Core/AST/StructuredCommands/ByProofCmd.cs |  7 ++-
 Source/Core/AST/StructuredCommands/IfCmd.cs   | 43 +++++++++----
 .../AST/StructuredCommands/StructuredCmd.cs   |  8 ++-
 .../Core/AST/StructuredCommands/WhileCmd.cs   | 18 +++---
 6 files changed, 72 insertions(+), 78 deletions(-)

diff --git a/Source/Core/AST/BigBlocksResolutionContext.cs b/Source/Core/AST/BigBlocksResolutionContext.cs
index 3753558f2..7f3ee70eb 100644
--- a/Source/Core/AST/BigBlocksResolutionContext.cs
+++ b/Source/Core/AST/BigBlocksResolutionContext.cs
@@ -33,7 +33,7 @@ void ObjectInvariant()
     Contract.Invariant(ErrorHandler != null);
   }
 
-  public void ComputeAllLabels(StmtList stmts)
+  private void ComputeAllLabels(StmtList stmts)
   {
     if (stmts == null)
     {
@@ -47,18 +47,16 @@ public void ComputeAllLabels(StmtList stmts)
         allLabels.Add(bb.LabelName);
       }
 
-      bb.ec?.ComputeAllLabels(this);
-    }
-  }
-
-  private void ComputeAllLabels(StructuredCmd cmd)
-  {
-    if (cmd == null)
-    {
-      return;
+      if (bb.ec == null)
+      {
+        continue;
+      }
+      
+      foreach (var list in bb.ec.StatementLists)
+      {
+        ComputeAllLabels(list);
+      }
     }
-    
-    cmd.ComputeAllLabels(this);
   }
 
   public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
@@ -194,26 +192,14 @@ void NameAnonymousBlocks(StmtList stmtList)
         b.LabelName = FreshPrefix();
       }
 
-      if (b.ec is WhileCmd)
+      foreach (var l in b.ec.StatementLists)
       {
-        WhileCmd wcmd = (WhileCmd) b.ec;
-        NameAnonymousBlocks(wcmd.Body);
-      }
-      else
-      {
-        for (IfCmd ifcmd = b.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-        {
-          NameAnonymousBlocks(ifcmd.thn);
-          if (ifcmd.elseBlock != null)
-          {
-            NameAnonymousBlocks(ifcmd.elseBlock);
-          }
-        }
+        NameAnonymousBlocks(l);
       }
     }
   }
 
-  void RecordSuccessors(StmtList stmtList, BigBlock successor)
+  public void RecordSuccessors(StmtList stmtList, BigBlock successor)
   {
     Contract.Requires(stmtList != null);
     for (int i = stmtList.BigBlocks.Count; 0 <= --i;)
@@ -221,23 +207,7 @@ void RecordSuccessors(StmtList stmtList, BigBlock successor)
       BigBlock big = stmtList.BigBlocks[i];
       big.successorBigBlock = successor;
 
-      if (big.ec is WhileCmd)
-      {
-        WhileCmd wcmd = (WhileCmd) big.ec;
-        RecordSuccessors(wcmd.Body, big);
-      }
-      else
-      {
-        for (IfCmd ifcmd = big.ec as IfCmd; ifcmd != null; ifcmd = ifcmd.elseIf)
-        {
-          RecordSuccessors(ifcmd.thn, successor);
-          if (ifcmd.elseBlock != null)
-          {
-            RecordSuccessors(ifcmd.elseBlock, successor);
-          }
-        }
-      }
-
+      big.ec.RecordSuccessors(this, big);
       successor = big;
     }
   }
@@ -293,7 +263,7 @@ public void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
       }
       else
       {
-        b.ec.CreateBlocks(this, b, theSimpleCmds, stmtList, n == 0 ? runOffTheEndLabel : null);
+        b.ec.CreateBlocks(this, b, theSimpleCmds, n == 0 ? runOffTheEndLabel : null);
       }
     }
   }
diff --git a/Source/Core/AST/StructuredCommands/BreakCmd.cs b/Source/Core/AST/StructuredCommands/BreakCmd.cs
index 158f8f466..4d30a955d 100644
--- a/Source/Core/AST/StructuredCommands/BreakCmd.cs
+++ b/Source/Core/AST/StructuredCommands/BreakCmd.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
+using System.Linq;
 
 namespace Microsoft.Boogie;
 
@@ -84,15 +85,16 @@ public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtLi
     }
   }
 
-  public override void ComputeAllLabels(BigBlocksResolutionContext context)
-  {
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
     string runOffTheEndLabel)
   {
     Contract.Assert(this.BreakEnclosure != null);
-    Block block = new Block(b.tok, b.LabelName, theSimpleCmds, BigBlocksResolutionContext.GotoSuccessor(b.ec.tok, BreakEnclosure));
+    Block block = new Block(bigBlock.tok, bigBlock.LabelName, theSimpleCmds, BigBlocksResolutionContext.GotoSuccessor(bigBlock.ec.tok, BreakEnclosure));
     context.AddBlock(block);
   }
+
+  public override IEnumerable<StmtList> StatementLists => Enumerable.Empty<StmtList>();
+  public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
+  {
+  }
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/ByProofCmd.cs b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
index 4fb49476c..818c50700 100644
--- a/Source/Core/AST/StructuredCommands/ByProofCmd.cs
+++ b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
@@ -26,13 +26,14 @@ public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtLi
     throw new System.NotImplementedException();
   }
 
-  public override void ComputeAllLabels(BigBlocksResolutionContext context)
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
+    string runOffTheEndLabel)
   {
     throw new System.NotImplementedException();
   }
 
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
-    string runOffTheEndLabel)
+  public override IEnumerable<StmtList> StatementLists => new[] { Body, Proof };
+  public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
   {
     throw new System.NotImplementedException();
   }
diff --git a/Source/Core/AST/StructuredCommands/IfCmd.cs b/Source/Core/AST/StructuredCommands/IfCmd.cs
index bbac4e709..c4a9300c5 100644
--- a/Source/Core/AST/StructuredCommands/IfCmd.cs
+++ b/Source/Core/AST/StructuredCommands/IfCmd.cs
@@ -134,18 +134,11 @@ public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtLi
     }
   }
 
-  public override void ComputeAllLabels(BigBlocksResolutionContext context)
-  {
-    context.ComputeAllLabels(thn);
-    elseIf.ComputeAllLabels(context);
-    context.ComputeAllLabels(elseBlock);
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds, StmtList stmtList,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
     string runOffTheEndLabel)
   {
-    IfCmd ifcmd = (IfCmd) b.ec;
-    string predLabel = b.LabelName;
+    IfCmd ifcmd = (IfCmd) bigBlock.ec;
+    string predLabel = bigBlock.LabelName;
     List<Cmd> predCmds = theSimpleCmds;
 
     for (; ifcmd != null; ifcmd = ifcmd.elseIf)
@@ -178,7 +171,7 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
       }
 
       // ... goto Then, Else;
-      var jumpBlock = new Block(b.tok, predLabel, predCmds,
+      var jumpBlock = new Block(bigBlock.tok, predLabel, predCmds,
         new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
       context.AddBlock(jumpBlock);
 
@@ -231,7 +224,7 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
         }
         else
         {
-          trCmd = BigBlocksResolutionContext.GotoSuccessor(ifcmd.tok, b);
+          trCmd = BigBlocksResolutionContext.GotoSuccessor(ifcmd.tok, bigBlock);
         }
 
         var block = new Block(ifcmd.tok, elseLabel, ssElse, trCmd);
@@ -239,4 +232,30 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
       }
     }
   }
+
+  public override IEnumerable<StmtList> StatementLists {
+    get
+    {
+      for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
+      {
+        yield return ifcmd.thn;
+        if (ifcmd.elseBlock != null)
+        {
+          yield return ifcmd.elseBlock;
+        }
+      }
+    }
+  }
+
+  public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
+  {
+    for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
+    {
+      context.RecordSuccessors(ifcmd.thn, bigBlock.successorBigBlock);
+      if (ifcmd.elseBlock != null)
+      {
+        context.RecordSuccessors(ifcmd.elseBlock, bigBlock.successorBigBlock);
+      }
+    }
+  }
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/StructuredCmd.cs b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
index cdf993ea0..ac386320f 100644
--- a/Source/Core/AST/StructuredCommands/StructuredCmd.cs
+++ b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
@@ -39,8 +39,10 @@ public StructuredCmd(IToken tok)
 
   public abstract void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context);
   public abstract void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock);
-  public abstract void ComputeAllLabels(BigBlocksResolutionContext context);
-  public abstract void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds,
-    StmtList stmtList,
+
+  public abstract void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
     string runOffTheEndLabel);
+
+  public abstract IEnumerable<StmtList> StatementLists { get; }
+  public abstract void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock);
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/WhileCmd.cs b/Source/Core/AST/StructuredCommands/WhileCmd.cs
index 99a99742e..80aa07cd1 100644
--- a/Source/Core/AST/StructuredCommands/WhileCmd.cs
+++ b/Source/Core/AST/StructuredCommands/WhileCmd.cs
@@ -92,13 +92,7 @@ public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtLi
     context.CheckLegalLabels(Body, stmtList, bigBlock);
   }
 
-  public override void ComputeAllLabels(BigBlocksResolutionContext context)
-  {
-    context.ComputeAllLabels(Body);
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b, List<Cmd> theSimpleCmds,
-    StmtList stmtList,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
     string runOffTheEndLabel)
   {
       WhileCmd wcmd = (WhileCmd) this;
@@ -124,7 +118,7 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
       bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
 
       // ... goto LoopHead;
-      Block block = new Block(b.tok, b.LabelName, theSimpleCmds,
+      Block block = new Block(bigBlock.tok, bigBlock.LabelName, theSimpleCmds,
         new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
       context.AddBlock(block);
 
@@ -163,10 +157,16 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
       }
       else
       {
-        trCmd = BigBlocksResolutionContext.GotoSuccessor(wcmd.tok, b);
+        trCmd = BigBlocksResolutionContext.GotoSuccessor(wcmd.tok, bigBlock);
       }
 
       block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
       context.AddBlock(block);
   }
+
+  public override IEnumerable<StmtList> StatementLists => new [] { Body };
+  public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
+  {
+    context.RecordSuccessors(Body, bigBlock);
+  }
 }
\ No newline at end of file

From d879869516f051b97fbe6dc3fe8ca9c57f138cff Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 16 Sep 2024 16:34:41 +0200
Subject: [PATCH 6/9] Renames

---
 Source/Concurrency/LinearTypeChecker.cs       |  14 +-
 Source/Core/AST/AbsyCmd.cs                    | 341 +-----------------
 Source/Core/AST/BigBlocksResolutionContext.cs | 152 ++++----
 Source/Core/AST/Block.cs                      |   3 +-
 Source/Core/AST/Cmd.cs                        | 173 +++++++++
 Source/Core/AST/Implementation.cs             |   4 +-
 Source/Core/AST/StateCmd.cs                   | 136 +++++++
 .../Core/AST/StructuredCommands/BreakCmd.cs   |  61 +---
 .../Core/AST/StructuredCommands/ByProofCmd.cs |  18 +-
 Source/Core/AST/StructuredCommands/IfCmd.cs   | 151 ++++----
 .../AST/StructuredCommands/StructuredCmd.cs   |   5 +-
 .../Core/AST/StructuredCommands/WhileCmd.cs   | 144 ++++----
 12 files changed, 555 insertions(+), 647 deletions(-)
 create mode 100644 Source/Core/AST/Cmd.cs
 create mode 100644 Source/Core/AST/StateCmd.cs

diff --git a/Source/Concurrency/LinearTypeChecker.cs b/Source/Concurrency/LinearTypeChecker.cs
index 69e48cd62..e0dfaa0ee 100644
--- a/Source/Concurrency/LinearTypeChecker.cs
+++ b/Source/Concurrency/LinearTypeChecker.cs
@@ -764,8 +764,8 @@ private void CheckLinearStoreAccessInGuards()
         while (stmtLists.Count > 0)
         {
           var stmtList = stmtLists.Pop();
-          stmtList.BigBlocks.Where(bigBlock => bigBlock.ec != null).ForEach(bigBlock => {
-            switch (bigBlock.ec) {
+          stmtList.BigBlocks.Where(bigBlock => bigBlock.Ec != null).ForEach(bigBlock => {
+            switch (bigBlock.Ec) {
               case IfCmd ifCmd:
                 void ProcessIfCmd(IfCmd ifCmd)
                 {
@@ -773,14 +773,14 @@ void ProcessIfCmd(IfCmd ifCmd)
                   {
                     checkingContext.Error(ifCmd.tok, "access to linear store not allowed");
                   }
-                  stmtLists.Push(ifCmd.thn);
-                  if (ifCmd.elseIf != null)
+                  stmtLists.Push(ifCmd.Thn);
+                  if (ifCmd.ElseIf != null)
                   {
-                    ProcessIfCmd(ifCmd.elseIf);
+                    ProcessIfCmd(ifCmd.ElseIf);
                   }
-                  else if (ifCmd.elseBlock != null)
+                  else if (ifCmd.ElseBlock != null)
                   {
-                    stmtLists.Push(ifCmd.elseBlock);
+                    stmtLists.Push(ifCmd.ElseBlock);
                   }
                 }
                 ProcessIfCmd(ifCmd);
diff --git a/Source/Core/AST/AbsyCmd.cs b/Source/Core/AST/AbsyCmd.cs
index 408619a1f..7296082ce 100644
--- a/Source/Core/AST/AbsyCmd.cs
+++ b/Source/Core/AST/AbsyCmd.cs
@@ -16,12 +16,11 @@ void ObjectInvariant()
     {
       Contract.Invariant(tok != null);
       Contract.Invariant(Anonymous || this.labelName != null);
-      Contract.Invariant(this._ec == null || this._tc == null);
-      Contract.Invariant(this._simpleCmds != null);
+      Contract.Invariant(this.ec == null || this._tc == null);
+      Contract.Invariant(this.prefixCmds != null);
     }
 
-    public readonly IToken /*!*/
-      tok;
+    public readonly IToken /*!*/ tok;
 
     public readonly bool Anonymous;
 
@@ -41,34 +40,34 @@ public string LabelName
       }
     }
 
-    [Rep] private List<Cmd> /*!*/ _simpleCmds;
+    [Rep] private List<Cmd> /*!*/ prefixCmds;
 
     /// <summary>
     /// These come before the structured command
     /// </summary>
-    public List<Cmd> /*!*/ simpleCmds
+    public List<Cmd> /*!*/ PrefixCmds
     {
       get
       {
         Contract.Ensures(Contract.Result<List<Cmd>>() != null);
-        return this._simpleCmds;
+        return this.prefixCmds;
       }
       set
       {
         Contract.Requires(value != null);
-        this._simpleCmds = value;
+        this.prefixCmds = value;
       }
     }
 
-    private StructuredCmd _ec;
+    private StructuredCmd ec;
 
-    public StructuredCmd ec
+    public StructuredCmd Ec
     {
-      get { return this._ec; }
+      get => ec;
       set
       {
         Contract.Requires(value == null || this.tc == null);
-        this._ec = value;
+        this.ec = value;
       }
     }
 
@@ -79,24 +78,23 @@ public TransferCmd tc
       get { return this._tc; }
       set
       {
-        Contract.Requires(value == null || this.ec == null);
+        Contract.Requires(value == null || this.Ec == null);
         this._tc = value;
       }
     }
 
-    public BigBlock
-      successorBigBlock; // semantic successor (may be a back-edge, pointing back to enclosing while statement); null if successor is end of procedure body (or if field has not yet been initialized)
+    public BigBlock Successor; // semantic successor (may be a back-edge, pointing back to enclosing while statement); null if successor is end of procedure body (or if field has not yet been initialized)
 
-    public BigBlock(IToken tok, string labelName, [Captured] List<Cmd> simpleCmds, StructuredCmd ec, TransferCmd tc)
+    public BigBlock(IToken tok, string labelName, [Captured] List<Cmd> prefixCmds, StructuredCmd ec, TransferCmd tc)
     {
-      Contract.Requires(simpleCmds != null);
+      Contract.Requires(prefixCmds != null);
       Contract.Requires(tok != null);
       Contract.Requires(ec == null || tc == null);
       this.tok = tok;
       this.Anonymous = labelName == null;
       this.labelName = labelName;
-      this._simpleCmds = simpleCmds;
-      this._ec = ec;
+      this.prefixCmds = prefixCmds;
+      this.ec = ec;
       this._tc = tc;
     }
 
@@ -111,15 +109,15 @@ public void Emit(TokenTextWriter stream, int level)
             : this.LabelName);
       }
 
-      foreach (Cmd /*!*/ c in this.simpleCmds)
+      foreach (Cmd /*!*/ c in this.PrefixCmds)
       {
         Contract.Assert(c != null);
         c.Emit(stream, level + 1);
       }
 
-      if (this.ec != null)
+      if (this.Ec != null)
       {
-        this.ec.Emit(stream, level + 1);
+        this.Ec.Emit(stream, level + 1);
       }
       else if (this.tc != null)
       {
@@ -505,174 +503,6 @@ public static byte[] CombineChecksums(byte[] first, byte[] second, bool unordere
     }
   }
 
-  /// <summary>
-  /// Could have also been called a statement.
-  ///
-  /// Does not include commands that contain other commands,
-  /// for those, look at StructuredCmd
-  /// 
-  /// </summary>
-  [ContractClass(typeof(CmdContracts))]
-  public abstract class Cmd : Absy
-  {
-    public List<int> Layers;
-    
-    public byte[] Checksum { get; internal set; }
-    public byte[] SugaredCmdChecksum { get; internal set; }
-    public bool IrrelevantForChecksumComputation { get; set; }
-
-    public Cmd(IToken /*!*/ tok)
-      : base(tok)
-    {
-      Contract.Assert(tok != null);
-    }
-
-    public abstract void Emit(TokenTextWriter /*!*/ stream, int level);
-
-    /// <summary>
-    /// Should only be called after resolution
-    /// </summary>
-    public IEnumerable<Variable> GetAssignedVariables() {
-      List<IdentifierExpr> ids = new();
-      AddAssignedIdentifiers(ids);
-      return ids.Select(id => id.Decl);
-    }
-    
-    public abstract void AddAssignedIdentifiers(List<IdentifierExpr> /*!*/ vars);
-
-    public void CheckAssignments(TypecheckingContext tc)
-    {
-      Contract.Requires(tc != null);
-      var /*!*/ vars = GetAssignedVariables().ToList();
-      foreach (Variable /*!*/ v in vars)
-      {
-        Contract.Assert(v != null);
-        if (!v.IsMutable)
-        {
-          tc.Error(this, "command assigns to an immutable variable: {0}", v.Name);
-        }
-        else if (tc.CheckModifies && v is GlobalVariable)
-        {
-          if (!tc.Yields && !tc.InFrame(v))
-          {
-            tc.Error(this,
-              "command assigns to a global variable that is not in the enclosing {0} modifies clause: {1}",
-              tc.Proc is ActionDecl ? "action's" : "procedure's", v.Name);
-          }
-        }
-      }
-    }
-
-    // Methods to simulate the old SimpleAssignCmd and MapAssignCmd
-    public static AssignCmd SimpleAssign(IToken tok, IdentifierExpr lhs, Expr rhs)
-    {
-      Contract.Requires(rhs != null);
-      Contract.Requires(lhs != null);
-      Contract.Requires(tok != null);
-      Contract.Ensures(Contract.Result<AssignCmd>() != null);
-      List<AssignLhs /*!*/> /*!*/
-        lhss = new List<AssignLhs /*!*/>();
-      List<Expr /*!*/> /*!*/
-        rhss = new List<Expr /*!*/>();
-
-      lhss.Add(new SimpleAssignLhs(lhs.tok, lhs));
-      rhss.Add(rhs);
-
-      return new AssignCmd(tok, lhss, rhss);
-    }
-
-    public static AssignCmd /*!*/ MapAssign(IToken tok,
-      IdentifierExpr /*!*/ map,
-      List<Expr> /*!*/ indexes, Expr /*!*/ rhs)
-    {
-      Contract.Requires(tok != null);
-      Contract.Requires(map != null);
-      Contract.Requires(indexes != null);
-      Contract.Requires(rhs != null);
-      Contract.Ensures(Contract.Result<AssignCmd>() != null);
-      List<AssignLhs /*!*/> /*!*/
-        lhss = new List<AssignLhs /*!*/>();
-      List<Expr /*!*/> /*!*/
-        rhss = new List<Expr /*!*/>();
-      List<Expr /*!*/> /*!*/
-        indexesList = new List<Expr /*!*/>();
-
-
-      foreach (Expr e in indexes)
-      {
-        indexesList.Add(cce.NonNull(e));
-      }
-
-      lhss.Add(new MapAssignLhs(map.tok,
-        new SimpleAssignLhs(map.tok, map),
-        indexesList));
-      rhss.Add(rhs);
-
-      return new AssignCmd(tok, lhss, rhss);
-    }
-
-    public static AssignCmd /*!*/ MapAssign(IToken tok,
-      IdentifierExpr /*!*/ map,
-      params Expr[] /*!*/ args)
-    {
-      Contract.Requires(tok != null);
-      Contract.Requires(map != null);
-      Contract.Requires(args != null);
-      Contract.Requires(args.Length > 0); // at least the rhs
-      Contract.Requires(Contract.ForAll(args, i => i != null));
-      Contract.Ensures(Contract.Result<AssignCmd>() != null);
-
-      List<AssignLhs /*!*/> /*!*/
-        lhss = new List<AssignLhs /*!*/>();
-      List<Expr /*!*/> /*!*/
-        rhss = new List<Expr /*!*/>();
-      List<Expr /*!*/> /*!*/
-        indexesList = new List<Expr /*!*/>();
-
-      for (int i = 0; i < args.Length - 1; ++i)
-      {
-        indexesList.Add(cce.NonNull(args[i]));
-      }
-
-      lhss.Add(new MapAssignLhs(map.tok,
-        new SimpleAssignLhs(map.tok, map),
-        indexesList));
-      rhss.Add(cce.NonNull(args[args.Length - 1]));
-
-      return new AssignCmd(tok, lhss, rhss);
-    }
-
-    /// <summary>
-    /// This is a helper routine for printing a linked list of attributes.  Each attribute
-    /// is terminated by a space.
-    /// </summary>
-    public static void EmitAttributes(TokenTextWriter stream, QKeyValue attributes)
-    {
-      Contract.Requires(stream != null);
-
-      if (stream.UseForComputingChecksums)
-      {
-        return;
-      }
-
-      for (QKeyValue kv = attributes; kv != null; kv = kv.Next)
-      {
-        kv.Emit(stream);
-        stream.Write(" ");
-      }
-    }
-
-    [Pure]
-    public override string ToString() {
-      Contract.Ensures(Contract.Result<string>() != null);
-      System.IO.StringWriter buffer = new System.IO.StringWriter();
-      using TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, false, false, PrintOptions.Default);
-      this.Emit(stream, 0);
-
-      return buffer.ToString();
-    }
-  }
-  
   public class CommentCmd : Cmd // just a convenience for debugging
   {
     public readonly string /*!*/
@@ -1528,137 +1358,6 @@ protected override Cmd ComputeDesugaring(PrintOptions options)
     }
   }
 
-  /// <summary>
-  /// A StateCmd is like an imperative-let binding around a sequence of commands.
-  /// There is no user syntax for a StateCmd.  Instead, a StateCmd is only used
-  /// temporarily during the desugaring phase inside the VC generator.
-  /// </summary>
-  public class StateCmd : Cmd
-  {
-    [ContractInvariantMethod]
-    void ObjectInvariant()
-    {
-      Contract.Invariant(this._locals != null);
-      Contract.Invariant(this._cmds != null);
-    }
-
-    private List<Variable> _locals;
-
-    public /*readonly, except for the StandardVisitor*/ List<Variable> /*!*/ Locals
-    {
-      get
-      {
-        Contract.Ensures(Contract.Result<List<Variable>>() != null);
-        return this._locals;
-      }
-      internal set
-      {
-        Contract.Requires(value != null);
-        this._locals = value;
-      }
-    }
-
-    private List<Cmd> _cmds;
-
-    public /*readonly, except for the StandardVisitor*/ List<Cmd> /*!*/ Cmds
-    {
-      get
-      {
-        Contract.Ensures(Contract.Result<List<Cmd>>() != null);
-        return this._cmds;
-      }
-      set
-      {
-        Contract.Requires(value != null);
-        this._cmds = value;
-      }
-    }
-
-    public StateCmd(IToken tok, List<Variable> /*!*/ locals, List<Cmd> /*!*/ cmds)
-      : base(tok)
-    {
-      Contract.Requires(locals != null);
-      Contract.Requires(cmds != null);
-      Contract.Requires(tok != null);
-      this._locals = locals;
-      this._cmds = cmds;
-    }
-
-    public override void Resolve(ResolutionContext rc)
-    {
-      //Contract.Requires(rc != null);
-      rc.PushVarContext();
-      foreach (Variable /*!*/ v in Locals)
-      {
-        Contract.Assert(v != null);
-        rc.AddVariable(v);
-      }
-
-      foreach (Cmd /*!*/ cmd in Cmds)
-      {
-        Contract.Assert(cmd != null);
-        cmd.Resolve(rc);
-      }
-
-      rc.PopVarContext();
-    }
-
-    public override void AddAssignedIdentifiers(List<IdentifierExpr> vars) {
-      var vs = new List<IdentifierExpr>();
-      foreach (Cmd cmd in Cmds)
-      {
-        Contract.Assert(cmd != null);
-        cmd.AddAssignedIdentifiers(vs);
-      }
-
-      var localsSet = new HashSet<Variable>(this.Locals);
-      foreach (var v in vs)
-      {
-        Debug.Assert(v.Decl != null);
-        if (!localsSet.Contains(v.Decl))
-        {
-          vars.Add(v);
-        }
-      }
-    }
-
-    public override void Typecheck(TypecheckingContext tc)
-    {
-      //Contract.Requires(tc != null);
-      foreach (Cmd /*!*/ cmd in Cmds)
-      {
-        Contract.Assert(cmd != null);
-        cmd.Typecheck(tc);
-      }
-    }
-
-    public override void Emit(TokenTextWriter stream, int level)
-    {
-      //Contract.Requires(stream != null);
-      stream.WriteLine(this, level, "{");
-      foreach (Variable /*!*/ v in Locals)
-      {
-        Contract.Assert(v != null);
-        v.Emit(stream, level + 1);
-      }
-
-      foreach (Cmd /*!*/ c in Cmds)
-      {
-        Contract.Assert(c != null);
-        c.Emit(stream, level + 1);
-      }
-
-      stream.WriteLine(level, "}");
-    }
-
-    public override Absy StdDispatch(StandardVisitor visitor)
-    {
-      //Contract.Requires(visitor != null);
-      Contract.Ensures(Contract.Result<Absy>() != null);
-      return visitor.VisitStateCmd(this);
-    }
-  }
-
   [ContractClass(typeof(SugaredCmdContracts))]
   public abstract class SugaredCmd : Cmd
   {
diff --git a/Source/Core/AST/BigBlocksResolutionContext.cs b/Source/Core/AST/BigBlocksResolutionContext.cs
index 7f3ee70eb..dcce234f9 100644
--- a/Source/Core/AST/BigBlocksResolutionContext.cs
+++ b/Source/Core/AST/BigBlocksResolutionContext.cs
@@ -6,27 +6,23 @@ namespace Microsoft.Boogie;
 
 public class BigBlocksResolutionContext
 {
-  StmtList /*!*/ stmtList;
-
-  [Peer] List<Block /*!*/> blocks;
-
-  string /*!*/ prefix = "anon";
-
-  int anon = 0;
-
+  private readonly StmtList /*!*/ rootList;
+
+  [Peer] private List<Block /*!*/> blocks;
+  private string /*!*/ prefix = "anon";
+  private int anon = 0;
+  private readonly HashSet<string /*!*/> allLabels = new();
+  private Errors ErrorHandler { get; }
+  
   public string FreshPrefix()
   {
     return prefix + anon++;
   }
 
-  HashSet<string /*!*/> allLabels = new();
-
-  public Errors ErrorHandler { get; }
-
   [ContractInvariantMethod]
   void ObjectInvariant()
   {
-    Contract.Invariant(stmtList != null);
+    Contract.Invariant(rootList != null);
     Contract.Invariant(cce.NonNullElements(blocks, true));
     Contract.Invariant(prefix != null);
     Contract.Invariant(cce.NonNullElements(allLabels, true));
@@ -47,28 +43,29 @@ private void ComputeAllLabels(StmtList stmts)
         allLabels.Add(bb.LabelName);
       }
 
-      if (bb.ec == null)
+      if (bb.Ec == null)
       {
         continue;
       }
       
-      foreach (var list in bb.ec.StatementLists)
+      foreach (var list in bb.Ec.StatementLists)
       {
         ComputeAllLabels(list);
       }
     }
   }
 
-  public BigBlocksResolutionContext(StmtList stmtList, Errors errorHandler)
+  public BigBlocksResolutionContext(StmtList rootList, Errors errorHandler)
   {
     Contract.Requires(errorHandler != null);
-    Contract.Requires(stmtList != null);
-    this.stmtList = stmtList;
+    Contract.Requires(rootList != null);
+    this.rootList = rootList;
+    this.ErrorHandler = errorHandler;
+    
     // Inject an empty big block at the end of the body of a while loop if its current end is another while loop.
     // This transformation creates a suitable jump target for break statements inside the nested while loop.
-    InjectEmptyBigBlockInsideWhileLoopBody(stmtList);
-    this.ErrorHandler = errorHandler;
-    ComputeAllLabels(stmtList);
+    InjectEmptyBigBlockInsideWhileLoopBody(rootList);
+    ComputeAllLabels(rootList);
   }
 
   public void AddBlock(Block block)
@@ -76,46 +73,62 @@ public void AddBlock(Block block)
     blocks.Add(block);
   }
 
-  public List<Block /*!*/> /*!*/ Blocks
+  public List<Block /*!*/> /*!*/ GetOrComputeBlocks
   {
     get
     {
       Contract.Ensures(cce.NonNullElements(Contract.Result<List<Block>>()));
-      if (blocks == null)
+      if (blocks != null)
       {
-        blocks = new List<Block /*!*/>();
+        return blocks;
+      }
 
-        int startErrorCount = this.ErrorHandler.count;
-        // Check that all goto statements go to a label in allLabels, and no break statement to a non-enclosing loop.
-        // Also, determine a good value for "prefix".
-        CheckLegalLabels(stmtList, null, null);
+      blocks = new List<Block /*!*/>();
 
-        // fill in names of anonymous blocks
-        NameAnonymousBlocks(stmtList);
+      int startErrorCount = this.ErrorHandler.count;
+      // Check that all goto statements go to a label in allLabels, and no break statement to a non-enclosing loop.
+      // Also, determine a good value for "prefix".
+      CheckLegalLabels(rootList, null, null);
 
-        // determine successor blocks
-        RecordSuccessors(stmtList, null);
+      // fill in names of anonymous blocks
+      NameAnonymousBlocks(rootList);
 
-        if (this.ErrorHandler.count == startErrorCount)
-        {
-          // generate blocks from the big blocks
-          CreateBlocks(stmtList, null);
-        }
+      // determine successor blocks
+      RecordSuccessors(rootList, null);
+
+      if (this.ErrorHandler.count == startErrorCount)
+      {
+        // generate blocks from the big blocks
+        CreateBlocks(rootList, null);
       }
 
       return blocks;
     }
   }
 
-  public void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
+  private static void InjectEmptyBigBlockInsideWhileLoopBody(StmtList stmtList)
   {
     foreach (var bb in stmtList.BigBlocks)
     {
-      bb.ec.InjectEmptyBigBlockInsideWhileLoopBody(this);
+      foreach (var childList in bb.Ec.StatementLists)
+      {
+        InjectEmptyBigBlockInsideWhileLoopBody(childList);
+      }
+
+      if (bb.Ec is not WhileCmd whileCmd)
+      {
+        continue;
+      }
+
+      var newBigBlocks = new List<BigBlock>(whileCmd.Body.BigBlocks)
+      {
+        new(Token.NoToken, null, new List<Cmd>(), null, null)
+      };
+      whileCmd.Body = new StmtList(newBigBlocks, whileCmd.Body.EndCurly);
     }
   }
 
-  public void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
+  private void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock parentBigBlock)
   {
     Contract.Requires(stmtList != null);
     Contract.Requires((parentContext == null) == (parentBigBlock == null));
@@ -148,13 +161,12 @@ public void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock
     }
 
     // check that labels in this and nested StmtList's are legal
-    foreach (BigBlock b in stmtList.BigBlocks)
+    foreach (var bigBlock in stmtList.BigBlocks)
     {
       // goto's must reference blocks in enclosing blocks
-      if (b.tc is GotoCmd)
+      if (bigBlock.tc is GotoCmd gotoCmd)
       {
-        GotoCmd g = (GotoCmd) b.tc;
-        foreach (string /*!*/ lbl in cce.NonNull(g.labelNames))
+        foreach (string /*!*/ lbl in cce.NonNull(gotoCmd.labelNames))
         {
           Contract.Assert(lbl != null);
           /*
@@ -171,28 +183,28 @@ public void CheckLegalLabels(StmtList stmtList, StmtList parentContext, BigBlock
             */
           if (!allLabels.Contains(lbl))
           {
-            this.ErrorHandler.SemErr(g.tok, "Error: goto label '" + lbl + "' is undefined");
+            this.ErrorHandler.SemErr(gotoCmd.tok, "Error: goto label '" + lbl + "' is undefined");
           }
         }
       }
       else
       {
-        b.ec.CheckLegalLabels(this, this.stmtList, b);
+        foreach (var childList in bigBlock.Ec.StatementLists)
+        {
+          CheckLegalLabels(childList, this.rootList, bigBlock); 
+        }
       }
     }
   }
 
-  void NameAnonymousBlocks(StmtList stmtList)
+  private void NameAnonymousBlocks(StmtList stmtList)
   {
     Contract.Requires(stmtList != null);
-    foreach (BigBlock b in stmtList.BigBlocks)
+    foreach (var b in stmtList.BigBlocks)
     {
-      if (b.LabelName == null)
-      {
-        b.LabelName = FreshPrefix();
-      }
+      b.LabelName ??= FreshPrefix();
 
-      foreach (var l in b.ec.StatementLists)
+      foreach (var l in b.Ec.StatementLists)
       {
         NameAnonymousBlocks(l);
       }
@@ -205,9 +217,9 @@ public void RecordSuccessors(StmtList stmtList, BigBlock successor)
     for (int i = stmtList.BigBlocks.Count; 0 <= --i;)
     {
       BigBlock big = stmtList.BigBlocks[i];
-      big.successorBigBlock = successor;
+      big.Successor = successor;
 
-      big.ec.RecordSuccessors(this, big);
+      big.Ec.RecordSuccessors(this, big);
       successor = big;
     }
   }
@@ -218,52 +230,52 @@ public void CreateBlocks(StmtList stmtList, string runOffTheEndLabel)
   {
     Contract.Requires(stmtList != null);
     Contract.Requires(blocks != null);
-    List<Cmd> cmdPrefixToApply = stmtList.PrefixCommands;
+    var cmdPrefixToApply = stmtList.PrefixCommands;
 
     int n = stmtList.BigBlocks.Count;
-    foreach (BigBlock b in stmtList.BigBlocks)
+    foreach (var childBigBlock in stmtList.BigBlocks)
     {
       n--;
-      Contract.Assert(b.LabelName != null);
+      Contract.Assert(childBigBlock.LabelName != null);
       List<Cmd> theSimpleCmds;
       if (cmdPrefixToApply == null)
       {
-        theSimpleCmds = b.simpleCmds;
+        theSimpleCmds = childBigBlock.PrefixCmds;
       }
       else
       {
         theSimpleCmds = new List<Cmd>();
         theSimpleCmds.AddRange(cmdPrefixToApply);
-        theSimpleCmds.AddRange(b.simpleCmds);
+        theSimpleCmds.AddRange(childBigBlock.PrefixCmds);
         cmdPrefixToApply = null; // now, we've used 'em up
       }
 
-      if (b.tc != null)
+      if (childBigBlock.tc != null)
       {
         // this BigBlock has the very same components as a Block
-        Contract.Assert(b.ec == null);
-        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, b.tc);
+        Contract.Assert(childBigBlock.Ec == null);
+        var block = new Block(childBigBlock.tok, childBigBlock.LabelName, theSimpleCmds, childBigBlock.tc);
         blocks.Add(block);
       }
-      else if (b.ec == null)
+      else if (childBigBlock.Ec == null)
       {
         TransferCmd trCmd;
         if (n == 0 && runOffTheEndLabel != null)
         {
           // goto the given label instead of the textual successor block
-          trCmd = new GotoCmd(stmtList.EndCurly, new List<String> {runOffTheEndLabel});
+          trCmd = new GotoCmd(stmtList.EndCurly, new List<string> {runOffTheEndLabel});
         }
         else
         {
-          trCmd = GotoSuccessor(stmtList.EndCurly, b);
+          trCmd = GotoSuccessor(stmtList.EndCurly, childBigBlock);
         }
 
-        Block block = new Block(b.tok, b.LabelName, theSimpleCmds, trCmd);
+        Block block = new Block(childBigBlock.tok, childBigBlock.LabelName, theSimpleCmds, trCmd);
         blocks.Add(block);
       }
       else
       {
-        b.ec.CreateBlocks(this, b, theSimpleCmds, n == 0 ? runOffTheEndLabel : null);
+        childBigBlock.Ec.CreateBlocks(this, childBigBlock, theSimpleCmds, n == 0 ? runOffTheEndLabel : null);
       }
     }
   }
@@ -273,9 +285,9 @@ public static TransferCmd GotoSuccessor(IToken tok, BigBlock b)
     Contract.Requires(b != null);
     Contract.Requires(tok != null);
     Contract.Ensures(Contract.Result<TransferCmd>() != null);
-    if (b.successorBigBlock != null)
+    if (b.Successor != null)
     {
-      return new GotoCmd(tok, new List<String> {b.successorBigBlock.LabelName});
+      return new GotoCmd(tok, new List<String> {b.Successor.LabelName});
     }
     else
     {
diff --git a/Source/Core/AST/Block.cs b/Source/Core/AST/Block.cs
index bcc077050..f5680c764 100644
--- a/Source/Core/AST/Block.cs
+++ b/Source/Core/AST/Block.cs
@@ -49,8 +49,7 @@ public IEnumerable<Block> Exits()
   }
 
   [Rep] //PM: needed to verify Traverse.Visit
-  public TransferCmd
-    TransferCmd; // maybe null only because we allow deferred initialization (necessary for cyclic structures)
+  public TransferCmd TransferCmd; // maybe null only because we allow deferred initialization (necessary for cyclic structures)
 
   public byte[] Checksum;
 
diff --git a/Source/Core/AST/Cmd.cs b/Source/Core/AST/Cmd.cs
new file mode 100644
index 000000000..80238910b
--- /dev/null
+++ b/Source/Core/AST/Cmd.cs
@@ -0,0 +1,173 @@
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+using System.Linq;
+
+namespace Microsoft.Boogie;
+
+/// <summary>
+/// Could have also been called a statement.
+///
+/// Does not include commands that contain other commands,
+/// for those, look at StructuredCmd
+/// 
+/// </summary>
+[ContractClass(typeof(CmdContracts))]
+public abstract class Cmd : Absy
+{
+  public List<int> Layers;
+    
+  public byte[] Checksum { get; internal set; }
+  public byte[] SugaredCmdChecksum { get; internal set; }
+  public bool IrrelevantForChecksumComputation { get; set; }
+
+  public Cmd(IToken /*!*/ tok)
+    : base(tok)
+  {
+    Contract.Assert(tok != null);
+  }
+
+  public abstract void Emit(TokenTextWriter /*!*/ stream, int level);
+
+  /// <summary>
+  /// Should only be called after resolution
+  /// </summary>
+  public IEnumerable<Variable> GetAssignedVariables() {
+    List<IdentifierExpr> ids = new();
+    AddAssignedIdentifiers(ids);
+    return ids.Select(id => id.Decl);
+  }
+    
+  public abstract void AddAssignedIdentifiers(List<IdentifierExpr> /*!*/ vars);
+
+  protected void CheckAssignments(TypecheckingContext tc)
+  {
+    Contract.Requires(tc != null);
+    var /*!*/ vars = GetAssignedVariables().ToList();
+    foreach (Variable /*!*/ v in vars)
+    {
+      Contract.Assert(v != null);
+      if (!v.IsMutable)
+      {
+        tc.Error(this, "command assigns to an immutable variable: {0}", v.Name);
+      }
+      else if (tc.CheckModifies && v is GlobalVariable)
+      {
+        if (!tc.Yields && !tc.InFrame(v))
+        {
+          tc.Error(this,
+            "command assigns to a global variable that is not in the enclosing {0} modifies clause: {1}",
+            tc.Proc is ActionDecl ? "action's" : "procedure's", v.Name);
+        }
+      }
+    }
+  }
+
+  // Methods to simulate the old SimpleAssignCmd and MapAssignCmd
+  public static AssignCmd SimpleAssign(IToken tok, IdentifierExpr lhs, Expr rhs)
+  {
+    Contract.Requires(rhs != null);
+    Contract.Requires(lhs != null);
+    Contract.Requires(tok != null);
+    Contract.Ensures(Contract.Result<AssignCmd>() != null);
+    List<AssignLhs /*!*/> /*!*/
+      lhss = new List<AssignLhs /*!*/>();
+    List<Expr /*!*/> /*!*/
+      rhss = new List<Expr /*!*/>();
+
+    lhss.Add(new SimpleAssignLhs(lhs.tok, lhs));
+    rhss.Add(rhs);
+
+    return new AssignCmd(tok, lhss, rhss);
+  }
+
+  public static AssignCmd /*!*/ MapAssign(IToken tok,
+    IdentifierExpr /*!*/ map,
+    List<Expr> /*!*/ indexes, Expr /*!*/ rhs)
+  {
+    Contract.Requires(tok != null);
+    Contract.Requires(map != null);
+    Contract.Requires(indexes != null);
+    Contract.Requires(rhs != null);
+    Contract.Ensures(Contract.Result<AssignCmd>() != null);
+    List<AssignLhs /*!*/> /*!*/
+      lhss = new List<AssignLhs /*!*/>();
+    List<Expr /*!*/> /*!*/
+      rhss = new List<Expr /*!*/>();
+    List<Expr /*!*/> /*!*/
+      indexesList = new List<Expr /*!*/>();
+
+
+    foreach (Expr e in indexes)
+    {
+      indexesList.Add(cce.NonNull(e));
+    }
+
+    lhss.Add(new MapAssignLhs(map.tok,
+      new SimpleAssignLhs(map.tok, map),
+      indexesList));
+    rhss.Add(rhs);
+
+    return new AssignCmd(tok, lhss, rhss);
+  }
+
+  public static AssignCmd /*!*/ MapAssign(IToken tok,
+    IdentifierExpr /*!*/ map,
+    params Expr[] /*!*/ args)
+  {
+    Contract.Requires(tok != null);
+    Contract.Requires(map != null);
+    Contract.Requires(args != null);
+    Contract.Requires(args.Length > 0); // at least the rhs
+    Contract.Requires(Contract.ForAll(args, i => i != null));
+    Contract.Ensures(Contract.Result<AssignCmd>() != null);
+
+    List<AssignLhs /*!*/> /*!*/
+      lhss = new List<AssignLhs /*!*/>();
+    List<Expr /*!*/> /*!*/
+      rhss = new List<Expr /*!*/>();
+    List<Expr /*!*/> /*!*/
+      indexesList = new List<Expr /*!*/>();
+
+    for (int i = 0; i < args.Length - 1; ++i)
+    {
+      indexesList.Add(cce.NonNull(args[i]));
+    }
+
+    lhss.Add(new MapAssignLhs(map.tok,
+      new SimpleAssignLhs(map.tok, map),
+      indexesList));
+    rhss.Add(cce.NonNull(args[^1]));
+
+    return new AssignCmd(tok, lhss, rhss);
+  }
+
+  /// <summary>
+  /// This is a helper routine for printing a linked list of attributes.  Each attribute
+  /// is terminated by a space.
+  /// </summary>
+  public static void EmitAttributes(TokenTextWriter stream, QKeyValue attributes)
+  {
+    Contract.Requires(stream != null);
+
+    if (stream.UseForComputingChecksums)
+    {
+      return;
+    }
+
+    for (QKeyValue kv = attributes; kv != null; kv = kv.Next)
+    {
+      kv.Emit(stream);
+      stream.Write(" ");
+    }
+  }
+
+  [Pure]
+  public override string ToString() {
+    Contract.Ensures(Contract.Result<string>() != null);
+    System.IO.StringWriter buffer = new System.IO.StringWriter();
+    using TokenTextWriter stream = new TokenTextWriter("<buffer>", buffer, false, false, PrintOptions.Default);
+    this.Emit(stream, 0);
+
+    return buffer.ToString();
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/Implementation.cs b/Source/Core/AST/Implementation.cs
index 9169f014b..8259d629a 100644
--- a/Source/Core/AST/Implementation.cs
+++ b/Source/Core/AST/Implementation.cs
@@ -388,8 +388,8 @@ public Implementation(IToken /*!*/ tok,
     Contract.Requires(errorHandler != null);
     LocVars = localVariables;
     StructuredStmts = structuredStmts;
-    BigBlocksResolutionContext ctx = new BigBlocksResolutionContext(structuredStmts, errorHandler);
-    Blocks = ctx.Blocks;
+    var ctx = new BigBlocksResolutionContext(structuredStmts, errorHandler);
+    Blocks = ctx.GetOrComputeBlocks;
     BlockPredecessorsComputed = false;
     scc = null;
     Attributes = kv;
diff --git a/Source/Core/AST/StateCmd.cs b/Source/Core/AST/StateCmd.cs
new file mode 100644
index 000000000..0df5c45e7
--- /dev/null
+++ b/Source/Core/AST/StateCmd.cs
@@ -0,0 +1,136 @@
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Boogie;
+
+/// <summary>
+/// A StateCmd is like an imperative-let binding around a sequence of commands.
+/// There is no user syntax for a StateCmd.  Instead, a StateCmd is only used
+/// temporarily during the desugaring phase inside the VC generator.
+/// </summary>
+public class StateCmd : Cmd
+{
+  [ContractInvariantMethod]
+  void ObjectInvariant()
+  {
+    Contract.Invariant(this.locals != null);
+    Contract.Invariant(this.cmds != null);
+  }
+
+  private List<Variable> locals;
+
+  public /*readonly, except for the StandardVisitor*/ List<Variable> /*!*/ Locals
+  {
+    get
+    {
+      Contract.Ensures(Contract.Result<List<Variable>>() != null);
+      return this.locals;
+    }
+    internal set
+    {
+      Contract.Requires(value != null);
+      this.locals = value;
+    }
+  }
+
+  private List<Cmd> cmds;
+
+  public /*readonly, except for the StandardVisitor*/ List<Cmd> /*!*/ Cmds
+  {
+    get
+    {
+      Contract.Ensures(Contract.Result<List<Cmd>>() != null);
+      return this.cmds;
+    }
+    set
+    {
+      Contract.Requires(value != null);
+      this.cmds = value;
+    }
+  }
+
+  public StateCmd(IToken tok, List<Variable> /*!*/ locals, List<Cmd> /*!*/ cmds)
+    : base(tok)
+  {
+    Contract.Requires(locals != null);
+    Contract.Requires(cmds != null);
+    Contract.Requires(tok != null);
+    this.locals = locals;
+    this.cmds = cmds;
+  }
+
+  public override void Resolve(ResolutionContext rc)
+  {
+    //Contract.Requires(rc != null);
+    rc.PushVarContext();
+    foreach (Variable /*!*/ v in Locals)
+    {
+      Contract.Assert(v != null);
+      rc.AddVariable(v);
+    }
+
+    foreach (Cmd /*!*/ cmd in Cmds)
+    {
+      Contract.Assert(cmd != null);
+      cmd.Resolve(rc);
+    }
+
+    rc.PopVarContext();
+  }
+
+  public override void AddAssignedIdentifiers(List<IdentifierExpr> vars) {
+    var vs = new List<IdentifierExpr>();
+    foreach (Cmd cmd in Cmds)
+    {
+      Contract.Assert(cmd != null);
+      cmd.AddAssignedIdentifiers(vs);
+    }
+
+    var localsSet = new HashSet<Variable>(this.Locals);
+    foreach (var v in vs)
+    {
+      Debug.Assert(v.Decl != null);
+      if (!localsSet.Contains(v.Decl))
+      {
+        vars.Add(v);
+      }
+    }
+  }
+
+  public override void Typecheck(TypecheckingContext tc)
+  {
+    //Contract.Requires(tc != null);
+    foreach (Cmd /*!*/ cmd in Cmds)
+    {
+      Contract.Assert(cmd != null);
+      cmd.Typecheck(tc);
+    }
+  }
+
+  public override void Emit(TokenTextWriter stream, int level)
+  {
+    //Contract.Requires(stream != null);
+    stream.WriteLine(this, level, "{");
+    foreach (Variable /*!*/ v in Locals)
+    {
+      Contract.Assert(v != null);
+      v.Emit(stream, level + 1);
+    }
+
+    foreach (Cmd /*!*/ c in Cmds)
+    {
+      Contract.Assert(c != null);
+      c.Emit(stream, level + 1);
+    }
+
+    stream.WriteLine(level, "}");
+  }
+
+  public override Absy StdDispatch(StandardVisitor visitor)
+  {
+    //Contract.Requires(visitor != null);
+    Contract.Ensures(Contract.Result<Absy>() != null);
+    return visitor.VisitStateCmd(this);
+  }
+}
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/BreakCmd.cs b/Source/Core/AST/StructuredCommands/BreakCmd.cs
index 4d30a955d..f02c266d3 100644
--- a/Source/Core/AST/StructuredCommands/BreakCmd.cs
+++ b/Source/Core/AST/StructuredCommands/BreakCmd.cs
@@ -28,68 +28,11 @@ public override void Emit(TokenTextWriter stream, int level)
     }
   }
 
-  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
-  {
-  }
-
-  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
-  {
-    Contract.Assert(BreakEnclosure == null); // it hasn't been initialized yet
-    bool found = false;
-    for (StmtList sl = stmtList; sl.ParentBigBlock != null; sl = sl.ParentContext)
-    {
-      cce.LoopInvariant(sl != null);
-      BigBlock bb = sl.ParentBigBlock;
-
-      if (Label == null)
-      {
-        // a label-less break statement breaks out of the innermost enclosing while statement
-        if (bb.ec is WhileCmd)
-        {
-          BreakEnclosure = bb;
-          found = true;
-          break;
-        }
-      }
-      else if (Label == bb.LabelName)
-      {
-        // a break statement with a label can break out of both if statements and while statements
-        if (bb.simpleCmds.Count == 0)
-        {
-          // this is a good target:  the label refers to the if/while statement
-          BreakEnclosure = bb;
-        }
-        else
-        {
-          // the label of bb refers to the first statement of bb, which in which case is a simple statement, not an if/while statement
-          context.ErrorHandler.SemErr(tok,
-            "Error: break label '" + Label + "' must designate an enclosing statement");
-        }
-
-        found = true; // don't look any further, since we've found a matching label
-        break;
-      }
-    }
-
-    if (!found)
-    {
-      if (Label == null)
-      {
-        context.ErrorHandler.SemErr(tok, "Error: break statement is not inside a loop");
-      }
-      else
-      {
-        context.ErrorHandler.SemErr(tok,
-          "Error: break label '" + Label + "' must designate an enclosing statement");
-      }
-    }
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
     string runOffTheEndLabel)
   {
     Contract.Assert(this.BreakEnclosure != null);
-    Block block = new Block(bigBlock.tok, bigBlock.LabelName, theSimpleCmds, BigBlocksResolutionContext.GotoSuccessor(bigBlock.ec.tok, BreakEnclosure));
+    Block block = new Block(bigBlock.tok, bigBlock.LabelName, incomingCommands, BigBlocksResolutionContext.GotoSuccessor(bigBlock.Ec.tok, BreakEnclosure));
     context.AddBlock(block);
   }
 
diff --git a/Source/Core/AST/StructuredCommands/ByProofCmd.cs b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
index 818c50700..32a78c6ea 100644
--- a/Source/Core/AST/StructuredCommands/ByProofCmd.cs
+++ b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
@@ -16,25 +16,17 @@ public override void Emit(TokenTextWriter stream, int level)
     throw new System.NotImplementedException();
   }
 
-  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
-  {
-    throw new System.NotImplementedException();
-  }
-
-  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
-  {
-    throw new System.NotImplementedException();
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
     string runOffTheEndLabel)
   {
-    throw new System.NotImplementedException();
+    bigBlock.LabelName
+    context.CreateBlocks(Proof, null);
+    context.CreateBlocks(Body, runOffTheEndLabel);
   }
 
   public override IEnumerable<StmtList> StatementLists => new[] { Body, Proof };
   public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
   {
-    throw new System.NotImplementedException();
+    context.RecordSuccessors(Body, bigBlock.Successor);
   }
 }
\ No newline at end of file
diff --git a/Source/Core/AST/StructuredCommands/IfCmd.cs b/Source/Core/AST/StructuredCommands/IfCmd.cs
index c4a9300c5..29207f0fa 100644
--- a/Source/Core/AST/StructuredCommands/IfCmd.cs
+++ b/Source/Core/AST/StructuredCommands/IfCmd.cs
@@ -6,12 +6,11 @@ namespace Microsoft.Boogie;
 
 public class IfCmd : StructuredCmd
 {
-  public Expr Guard;
+  public readonly Expr Guard;
 
-  private StmtList /*!*/
-    _thn;
+  private StmtList /*!*/ _thn;
 
-  public StmtList /*!*/ thn
+  public StmtList /*!*/ Thn
   {
     get
     {
@@ -25,27 +24,27 @@ public StmtList /*!*/ thn
     }
   }
 
-  private IfCmd _elseIf;
+  private IfCmd elseIf;
 
-  public IfCmd elseIf
+  public IfCmd ElseIf
   {
-    get { return this._elseIf; }
+    get => this.elseIf;
     set
     {
-      Contract.Requires(value == null || this.elseBlock == null);
-      this._elseIf = value;
+      Contract.Requires(value == null || this.ElseBlock == null);
+      this.elseIf = value;
     }
   }
 
-  private StmtList _elseBlock;
+  private StmtList elseBlock;
 
-  public StmtList elseBlock
+  public StmtList ElseBlock
   {
-    get { return this._elseBlock; }
+    get => this.elseBlock;
     set
     {
-      Contract.Requires(value == null || this.elseIf == null);
-      this._elseBlock = value;
+      Contract.Requires(value == null || this.ElseIf == null);
+      this.elseBlock = value;
     }
   }
 
@@ -53,7 +52,7 @@ public StmtList elseBlock
   void ObjectInvariant()
   {
     Contract.Invariant(this._thn != null);
-    Contract.Invariant(this._elseIf == null || this._elseBlock == null);
+    Contract.Invariant(this.elseIf == null || this.elseBlock == null);
   }
 
   public IfCmd(IToken /*!*/ tok, Expr guard, StmtList /*!*/ thn, IfCmd elseIf, StmtList elseBlock)
@@ -64,8 +63,8 @@ public IfCmd(IToken /*!*/ tok, Expr guard, StmtList /*!*/ thn, IfCmd elseIf, Stm
     Contract.Requires(elseIf == null || elseBlock == null);
     this.Guard = guard;
     this._thn = thn;
-    this._elseIf = elseIf;
-    this._elseBlock = elseBlock;
+    this.elseIf = elseIf;
+    this.elseBlock = elseBlock;
   }
 
   public override void Emit(TokenTextWriter stream, int level)
@@ -87,20 +86,20 @@ public override void Emit(TokenTextWriter stream, int level)
       stream.WriteLine(")");
 
       stream.WriteLine(level, "{");
-      ifcmd.thn.Emit(stream, level + 1);
+      ifcmd.Thn.Emit(stream, level + 1);
       stream.WriteLine(level, "}");
 
-      if (ifcmd.elseIf != null)
+      if (ifcmd.ElseIf != null)
       {
         stream.Write(level, "else if (");
-        ifcmd = ifcmd.elseIf;
+        ifcmd = ifcmd.ElseIf;
         continue;
       }
-      else if (ifcmd.elseBlock != null)
+      else if (ifcmd.ElseBlock != null)
       {
         stream.WriteLine(level, "else");
         stream.WriteLine(level, "{");
-        ifcmd.elseBlock.Emit(stream, level + 1);
+        ifcmd.ElseBlock.Emit(stream, level + 1);
         stream.WriteLine(level, "}");
       }
 
@@ -108,108 +107,86 @@ public override void Emit(TokenTextWriter stream, int level)
     }
   }
 
-  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
-  {
-    context.InjectEmptyBigBlockInsideWhileLoopBody(thn);
-    if (elseBlock != null)
-    {
-      context.InjectEmptyBigBlockInsideWhileLoopBody(elseBlock);
-    }
-
-    if (elseIf != null)
-    {
-      elseIf.InjectEmptyBigBlockInsideWhileLoopBody(context);
-    }
-  }
-
-  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
-  {
-    for (IfCmd ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
-    {
-      context.CheckLegalLabels(ifcmd.thn, stmtList, bigBlock);
-      if (ifcmd.elseBlock != null)
-      {
-        context.CheckLegalLabels(ifcmd.elseBlock, stmtList, bigBlock);
-      }
-    }
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
     string runOffTheEndLabel)
   {
-    IfCmd ifcmd = (IfCmd) bigBlock.ec;
-    string predLabel = bigBlock.LabelName;
-    List<Cmd> predCmds = theSimpleCmds;
+    var ifcmd = this;
+    string previousLabel = bigBlock.LabelName;
+    var previousCommands = incomingCommands;
 
-    for (; ifcmd != null; ifcmd = ifcmd.elseIf)
+    for (; ifcmd != null; ifcmd = ifcmd.ElseIf)
     {
       var prefix = context.FreshPrefix();
       string thenLabel = prefix + "_Then";
-      Contract.Assert(thenLabel != null);
       string elseLabel = prefix + "_Else";
-      Contract.Assert(elseLabel != null);
 
-      List<Cmd> ssThen = new List<Cmd>();
-      List<Cmd> ssElse = new List<Cmd>();
+      var ssThen = new List<Cmd>();
+      var ssElse = new List<Cmd>();
       if (ifcmd.Guard != null)
       {
-        var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard);
-        ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+        var ac = new AssumeCmd(ifcmd.tok, ifcmd.Guard)
+        {
+          Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null)
+        };
         ssThen.Add(ac);
 
-        ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-        ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
+        ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard))
+        {
+          Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null)
+        };
         ssElse.Add(ac);
       }
 
       // Try to squeeze in ssThen/ssElse into the first block of ifcmd.thn/ifcmd.elseBlock
-      bool thenGuardTakenCareOf = ifcmd.thn.PrefixFirstBlock(ssThen, ref thenLabel);
+      bool thenGuardTakenCareOf = ifcmd.Thn.PrefixFirstBlock(ssThen, ref thenLabel);
       bool elseGuardTakenCareOf = false;
-      if (ifcmd.elseBlock != null)
+      if (ifcmd.ElseBlock != null)
       {
-        elseGuardTakenCareOf = ifcmd.elseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
+        elseGuardTakenCareOf = ifcmd.ElseBlock.PrefixFirstBlock(ssElse, ref elseLabel);
       }
 
       // ... goto Then, Else;
-      var jumpBlock = new Block(bigBlock.tok, predLabel, predCmds,
-        new GotoCmd(ifcmd.tok, new List<String> {thenLabel, elseLabel}));
+      var jumpBlock = new Block(bigBlock.tok, previousLabel, previousCommands,
+        new GotoCmd(ifcmd.tok, new List<string> {thenLabel, elseLabel}));
       context.AddBlock(jumpBlock);
 
       if (!thenGuardTakenCareOf)
       {
         // Then: assume guard; goto firstThenBlock;
         var thenJumpBlock = new Block(ifcmd.tok, thenLabel, ssThen,
-          new GotoCmd(ifcmd.tok, new List<String> {ifcmd.thn.BigBlocks[0].LabelName}));
+          new GotoCmd(ifcmd.tok, new List<string> {ifcmd.Thn.BigBlocks[0].LabelName}));
         context.AddBlock(thenJumpBlock);
       }
 
       // recurse to create the blocks for the then branch
-      context.CreateBlocks(ifcmd.thn, runOffTheEndLabel);
+      context.CreateBlocks(ifcmd.Thn, runOffTheEndLabel);
 
-      if (ifcmd.elseBlock != null)
+      if (ifcmd.ElseBlock != null)
       {
-        Contract.Assert(ifcmd.elseIf == null);
+        Contract.Assert(ifcmd.ElseIf == null);
         if (!elseGuardTakenCareOf)
         {
           // Else: assume !guard; goto firstElseBlock;
           var elseJumpBlock = new Block(ifcmd.tok, elseLabel, ssElse,
-            new GotoCmd(ifcmd.tok, new List<String> {ifcmd.elseBlock.BigBlocks[0].LabelName}));
+            new GotoCmd(ifcmd.tok, new List<String> {ifcmd.ElseBlock.BigBlocks[0].LabelName}));
           context.AddBlock(elseJumpBlock);
         }
 
         // recurse to create the blocks for the else branch
-        context.CreateBlocks(ifcmd.elseBlock, runOffTheEndLabel);
+        context.CreateBlocks(ifcmd.ElseBlock, runOffTheEndLabel);
       }
-      else if (ifcmd.elseIf != null)
+      else if (ifcmd.ElseIf != null)
       {
         // this is an "else if"
-        predLabel = elseLabel;
-        predCmds = new List<Cmd>();
+        previousLabel = elseLabel;
+        previousCommands = new List<Cmd>();
         if (ifcmd.Guard != null)
         {
-          var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard));
-          ac.Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null);
-          predCmds.Add(ac);
+          var ac = new AssumeCmd(ifcmd.tok, Expr.Not(ifcmd.Guard))
+          {
+            Attributes = new QKeyValue(ifcmd.tok, "partition", new List<object>(), null)
+          };
+          previousCommands.Add(ac);
         }
       }
       else
@@ -220,7 +197,7 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
         if (runOffTheEndLabel != null)
         {
           // goto the given label instead of the textual successor block
-          trCmd = new GotoCmd(ifcmd.tok, new List<String> {runOffTheEndLabel});
+          trCmd = new GotoCmd(ifcmd.tok, new List<string> {runOffTheEndLabel});
         }
         else
         {
@@ -236,12 +213,12 @@ public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock b
   public override IEnumerable<StmtList> StatementLists {
     get
     {
-      for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
+      for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.ElseIf)
       {
-        yield return ifcmd.thn;
-        if (ifcmd.elseBlock != null)
+        yield return ifcmd.Thn;
+        if (ifcmd.ElseBlock != null)
         {
-          yield return ifcmd.elseBlock;
+          yield return ifcmd.ElseBlock;
         }
       }
     }
@@ -249,12 +226,12 @@ public override IEnumerable<StmtList> StatementLists {
 
   public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
   {
-    for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.elseIf)
+    for (var ifcmd = this; ifcmd != null; ifcmd = ifcmd.ElseIf)
     {
-      context.RecordSuccessors(ifcmd.thn, bigBlock.successorBigBlock);
-      if (ifcmd.elseBlock != null)
+      context.RecordSuccessors(ifcmd.Thn, bigBlock.Successor);
+      if (ifcmd.ElseBlock != null)
       {
-        context.RecordSuccessors(ifcmd.elseBlock, bigBlock.successorBigBlock);
+        context.RecordSuccessors(ifcmd.ElseBlock, bigBlock.Successor);
       }
     }
   }
diff --git a/Source/Core/AST/StructuredCommands/StructuredCmd.cs b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
index ac386320f..57be50ed6 100644
--- a/Source/Core/AST/StructuredCommands/StructuredCmd.cs
+++ b/Source/Core/AST/StructuredCommands/StructuredCmd.cs
@@ -37,10 +37,7 @@ public StructuredCmd(IToken tok)
 
   public abstract void Emit(TokenTextWriter /*!*/ stream, int level);
 
-  public abstract void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context);
-  public abstract void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock);
-
-  public abstract void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
+  public abstract void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
     string runOffTheEndLabel);
 
   public abstract IEnumerable<StmtList> StatementLists { get; }
diff --git a/Source/Core/AST/StructuredCommands/WhileCmd.cs b/Source/Core/AST/StructuredCommands/WhileCmd.cs
index 80aa07cd1..42e49da31 100644
--- a/Source/Core/AST/StructuredCommands/WhileCmd.cs
+++ b/Source/Core/AST/StructuredCommands/WhileCmd.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
-using System.Linq;
 
 namespace Microsoft.Boogie;
 
@@ -28,10 +27,10 @@ public WhileCmd(IToken tok, [Captured] Expr guard, List<PredicateCmd> invariants
     Contract.Requires(cce.NonNullElements(invariants));
     Contract.Requires(body != null);
     Contract.Requires(tok != null);
-    this.Guard = guard;
-    this.Invariants = invariants;
-    this.Yields = yields;
-    this.Body = body;
+    Guard = guard;
+    Invariants = invariants;
+    Yields = yields;
+    Body = body;
   }
 
   public override void Emit(TokenTextWriter stream, int level)
@@ -74,97 +73,78 @@ public override void Emit(TokenTextWriter stream, int level)
     stream.WriteLine(level, "}");
   }
 
-  public override void InjectEmptyBigBlockInsideWhileLoopBody(BigBlocksResolutionContext context)
+  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
+    string runOffTheEndLabel)
   {
-    context.InjectEmptyBigBlockInsideWhileLoopBody(Body);
-    if (Body.BigBlocks.Count <= 0 || Body.BigBlocks.Last().ec is not WhileCmd)
+    var prefix = context.FreshPrefix();
+    string loopHeadLabel = prefix + "_LoopHead";
+    string /*!*/ loopBodyLabel = prefix + "_LoopBody";
+    string loopDoneLabel = prefix + "_LoopDone";
+
+    List<Cmd> ssBody = new List<Cmd>();
+    List<Cmd> ssDone = new List<Cmd>();
+    if (Guard != null)
     {
-      return;
-    }
+      var ac = new AssumeCmd(tok, Guard);
+      ac.Attributes = new QKeyValue(tok, "partition", new List<object>(), null);
+      ssBody.Add(ac);
 
-    var newBigBlocks = new List<BigBlock>(Body.BigBlocks);
-    newBigBlocks.Add(new BigBlock(Token.NoToken, null, new List<Cmd>(), null, null));
-    Body = new StmtList(newBigBlocks, Body.EndCurly);
-  }
+      ac = new AssumeCmd(tok, Expr.Not(Guard));
+      ac.Attributes = new QKeyValue(tok, "partition", new List<object>(), null);
+      ssDone.Add(ac);
+    }
 
-  public override void CheckLegalLabels(BigBlocksResolutionContext context, StmtList stmtList, BigBlock bigBlock)
-  {
-    context.CheckLegalLabels(Body, stmtList, bigBlock);
-  }
+    // Try to squeeze in ssBody into the first block of wcmd.Body
+    bool bodyGuardTakenCareOf = Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
 
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> theSimpleCmds,
-    string runOffTheEndLabel)
-  {
-      WhileCmd wcmd = (WhileCmd) this;
-      var prefix = context.FreshPrefix();
-      string loopHeadLabel = prefix + "_LoopHead";
-      string /*!*/ loopBodyLabel = prefix + "_LoopBody";
-      string loopDoneLabel = prefix + "_LoopDone";
-
-      List<Cmd> ssBody = new List<Cmd>();
-      List<Cmd> ssDone = new List<Cmd>();
-      if (wcmd.Guard != null)
-      {
-        var ac = new AssumeCmd(wcmd.tok, wcmd.Guard);
-        ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-        ssBody.Add(ac);
+    // ... goto LoopHead;
+    Block block = new Block(bigBlock.tok, bigBlock.LabelName, incomingCommands,
+      new GotoCmd(tok, new List<String> {loopHeadLabel}));
+    context.AddBlock(block);
 
-        ac = new AssumeCmd(wcmd.tok, Expr.Not(wcmd.Guard));
-        ac.Attributes = new QKeyValue(wcmd.tok, "partition", new List<object>(), null);
-        ssDone.Add(ac);
-      }
+    // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
+    List<Cmd> ssHead = new List<Cmd>();
+    foreach (CallCmd yield in Yields)
+    {
+      ssHead.Add(yield);
+    }
+    foreach (PredicateCmd inv in Invariants)
+    {
+      ssHead.Add(inv);
+    }
 
-      // Try to squeeze in ssBody into the first block of wcmd.Body
-      bool bodyGuardTakenCareOf = wcmd.Body.PrefixFirstBlock(ssBody, ref loopBodyLabel);
+    block = new Block(tok, loopHeadLabel, ssHead,
+      new GotoCmd(tok, new List<String> {loopDoneLabel, loopBodyLabel}));
+    context.AddBlock(block);
 
-      // ... goto LoopHead;
-      Block block = new Block(bigBlock.tok, bigBlock.LabelName, theSimpleCmds,
-        new GotoCmd(wcmd.tok, new List<String> {loopHeadLabel}));
-      context.AddBlock(block);
-
-      // LoopHead: assert/assume loop_invariant; goto LoopDone, LoopBody;
-      List<Cmd> ssHead = new List<Cmd>();
-      foreach (CallCmd yield in wcmd.Yields)
-      {
-        ssHead.Add(yield);
-      }
-      foreach (PredicateCmd inv in wcmd.Invariants)
-      {
-        ssHead.Add(inv);
-      }
-
-      block = new Block(wcmd.tok, loopHeadLabel, ssHead,
-        new GotoCmd(wcmd.tok, new List<String> {loopDoneLabel, loopBodyLabel}));
+    if (!bodyGuardTakenCareOf)
+    {
+      // LoopBody: assume guard; goto firstLoopBlock;
+      block = new Block(tok, loopBodyLabel, ssBody,
+        new GotoCmd(tok, new List<String> {Body.BigBlocks[0].LabelName}));
       context.AddBlock(block);
+    }
 
-      if (!bodyGuardTakenCareOf)
-      {
-        // LoopBody: assume guard; goto firstLoopBlock;
-        block = new Block(wcmd.tok, loopBodyLabel, ssBody,
-          new GotoCmd(wcmd.tok, new List<String> {wcmd.Body.BigBlocks[0].LabelName}));
-        context.AddBlock(block);
-      }
-
-      // recurse to create the blocks for the loop body
-      context.CreateBlocks(wcmd.Body, loopHeadLabel);
+    // recurse to create the blocks for the loop body
+    context.CreateBlocks(Body, loopHeadLabel);
 
-      // LoopDone: assume !guard; goto loopSuccessor;
-      TransferCmd trCmd;
-      if (runOffTheEndLabel != null)
-      {
-        // goto the given label instead of the textual successor block
-        trCmd = new GotoCmd(wcmd.tok, new List<String> {runOffTheEndLabel});
-      }
-      else
-      {
-        trCmd = BigBlocksResolutionContext.GotoSuccessor(wcmd.tok, bigBlock);
-      }
+    // LoopDone: assume !guard; goto loopSuccessor;
+    TransferCmd trCmd;
+    if (runOffTheEndLabel != null)
+    {
+      // goto the given label instead of the textual successor block
+      trCmd = new GotoCmd(tok, new List<String> {runOffTheEndLabel});
+    }
+    else
+    {
+      trCmd = BigBlocksResolutionContext.GotoSuccessor(tok, bigBlock);
+    }
 
-      block = new Block(wcmd.tok, loopDoneLabel, ssDone, trCmd);
-      context.AddBlock(block);
+    block = new Block(tok, loopDoneLabel, ssDone, trCmd);
+    context.AddBlock(block);
   }
 
-  public override IEnumerable<StmtList> StatementLists => new [] { Body };
+  public override IEnumerable<StmtList> StatementLists => new[] { Body };
   public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
   {
     context.RecordSuccessors(Body, bigBlock);

From b03d169830a3a362632ea91c2abdd0afe259feb0 Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 23 Sep 2024 16:24:15 +0200
Subject: [PATCH 7/9] Allow marking variables so that they're not havocced
 after a loop

---
 Source/Core/AST/Absy.cs                       |  3 +-
 Source/Core/AST/CallCmd.cs                    |  6 ++--
 .../Core/AST/StructuredCommands/ByProofCmd.cs | 32 -------------------
 Source/VCGeneration/Split.cs                  |  4 +++
 .../VerificationConditionGenerator.cs         | 19 ++++++-----
 5 files changed, 17 insertions(+), 47 deletions(-)
 delete mode 100644 Source/Core/AST/StructuredCommands/ByProofCmd.cs

diff --git a/Source/Core/AST/Absy.cs b/Source/Core/AST/Absy.cs
index 307f898cf..c02f61267 100644
--- a/Source/Core/AST/Absy.cs
+++ b/Source/Core/AST/Absy.cs
@@ -1286,7 +1286,7 @@ void ObjectInvariant()
       Contract.Invariant(this.typedIdent != null);
     }
 
-    public Variable(IToken tok, TypedIdent typedIdent)
+    protected Variable(IToken tok, TypedIdent typedIdent)
       : base(tok, typedIdent.Name)
     {
       Contract.Requires(tok != null);
@@ -1304,6 +1304,7 @@ public Variable(IToken tok, TypedIdent typedIdent, QKeyValue kv)
     }
 
     public abstract bool IsMutable { get; }
+    public bool MayBeHavoccedAfterLoop { get; }
 
     public override void Emit(TokenTextWriter stream, int level)
     {
diff --git a/Source/Core/AST/CallCmd.cs b/Source/Core/AST/CallCmd.cs
index d39768d22..bf0c52a29 100644
--- a/Source/Core/AST/CallCmd.cs
+++ b/Source/Core/AST/CallCmd.cs
@@ -14,11 +14,9 @@ public class CallCmd : CallCommonality
 
   // Element of the following lists can be null, which means that
   // the call happens with * as these parameters
-  public List<Expr> /*!*/
-    Ins;
+  public List<Expr> /*!*/ Ins;
 
-  public List<IdentifierExpr> /*!*/
-    Outs;
+  public List<IdentifierExpr> /*!*/ Outs;
 
   [ContractInvariantMethod]
   void ObjectInvariant()
diff --git a/Source/Core/AST/StructuredCommands/ByProofCmd.cs b/Source/Core/AST/StructuredCommands/ByProofCmd.cs
deleted file mode 100644
index 32a78c6ea..000000000
--- a/Source/Core/AST/StructuredCommands/ByProofCmd.cs
+++ /dev/null
@@ -1,32 +0,0 @@
-using System.Collections.Generic;
-
-namespace Microsoft.Boogie;
-
-public class ByProofCmd : StructuredCmd
-{
-  public StmtList Body;
-  public StmtList Proof;
-  
-  public ByProofCmd(IToken tok) : base(tok)
-  {
-  }
-
-  public override void Emit(TokenTextWriter stream, int level)
-  {
-    throw new System.NotImplementedException();
-  }
-
-  public override void CreateBlocks(BigBlocksResolutionContext context, BigBlock bigBlock, List<Cmd> incomingCommands,
-    string runOffTheEndLabel)
-  {
-    bigBlock.LabelName
-    context.CreateBlocks(Proof, null);
-    context.CreateBlocks(Body, runOffTheEndLabel);
-  }
-
-  public override IEnumerable<StmtList> StatementLists => new[] { Body, Proof };
-  public override void RecordSuccessors(BigBlocksResolutionContext context, BigBlock bigBlock)
-  {
-    context.RecordSuccessors(Body, bigBlock.Successor);
-  }
-}
\ No newline at end of file
diff --git a/Source/VCGeneration/Split.cs b/Source/VCGeneration/Split.cs
index 7cf747118..89b2874aa 100644
--- a/Source/VCGeneration/Split.cs
+++ b/Source/VCGeneration/Split.cs
@@ -119,6 +119,10 @@ private void PrintSplitDeclarations(TokenTextWriter writer)
 
         foreach (var declaration in PrunedDeclarations.Except(functionAxioms.Concat(constantAxioms)).ToList())
         {
+          if (declaration is Implementation || declaration is Procedure)
+          {
+            continue;
+          }
           declaration.Emit(writer, 0);
         }
 
diff --git a/Source/VCGeneration/VerificationConditionGenerator.cs b/Source/VCGeneration/VerificationConditionGenerator.cs
index b53424ac4..d9a82286a 100644
--- a/Source/VCGeneration/VerificationConditionGenerator.cs
+++ b/Source/VCGeneration/VerificationConditionGenerator.cs
@@ -935,23 +935,22 @@ private void ConvertCFG2DAGStandard(Implementation impl, Dictionary<Block, List<
         #region Collect all variables that are assigned to in all of the natural loops for which this is the header
 
         List<Variable> varsToHavoc = VarsAssignedInLoop(g, header);
-        List<IdentifierExpr> havocExprs = new List<IdentifierExpr>();
-        foreach (Variable v in varsToHavoc)
+        var havocExprs = new HashSet<IdentifierExpr>();
+        foreach (Variable variable in varsToHavoc)
         {
-          Contract.Assert(v != null);
-          IdentifierExpr ie = new IdentifierExpr(Token.NoToken, v);
-          if (!havocExprs.Contains(ie))
+          Contract.Assert(variable != null);
+          if (variable.MayBeHavoccedAfterLoop)
           {
-            havocExprs.Add(ie);
+            continue;
           }
+          havocExprs.Add(new IdentifierExpr(Token.NoToken, variable));
         }
 
         // pass the token of the enclosing loop header to the HavocCmd so we can reconstruct
         // the source location for this later on
-        HavocCmd hc = new HavocCmd(header.tok, havocExprs);
-        List<Cmd> newCmds = new List<Cmd>();
-        newCmds.Add(hc);
-        foreach (Cmd c in header.Cmds)
+        HavocCmd hc = new HavocCmd(header.tok, havocExprs.ToList());
+        var newCmds = new List<Cmd> { hc };
+        foreach (var c in header.Cmds)
         {
           newCmds.Add(c);
         }

From 90ac56d6ddca857dab99aa11c65b021fd108d99a Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Mon, 23 Sep 2024 16:25:58 +0200
Subject: [PATCH 8/9] Rename

---
 Source/Core/AST/Absy.cs                               | 2 +-
 Source/VCGeneration/VerificationConditionGenerator.cs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Source/Core/AST/Absy.cs b/Source/Core/AST/Absy.cs
index c02f61267..1863112a8 100644
--- a/Source/Core/AST/Absy.cs
+++ b/Source/Core/AST/Absy.cs
@@ -1304,7 +1304,7 @@ public Variable(IToken tok, TypedIdent typedIdent, QKeyValue kv)
     }
 
     public abstract bool IsMutable { get; }
-    public bool MayBeHavoccedAfterLoop { get; }
+    public bool Monotonic { get; }
 
     public override void Emit(TokenTextWriter stream, int level)
     {
diff --git a/Source/VCGeneration/VerificationConditionGenerator.cs b/Source/VCGeneration/VerificationConditionGenerator.cs
index d9a82286a..40575c1cb 100644
--- a/Source/VCGeneration/VerificationConditionGenerator.cs
+++ b/Source/VCGeneration/VerificationConditionGenerator.cs
@@ -939,7 +939,7 @@ private void ConvertCFG2DAGStandard(Implementation impl, Dictionary<Block, List<
         foreach (Variable variable in varsToHavoc)
         {
           Contract.Assert(variable != null);
-          if (variable.MayBeHavoccedAfterLoop)
+          if (variable.Monotonic)
           {
             continue;
           }

From 8664d8abe675701f5fdfea6c3d068b85fc14c7da Mon Sep 17 00:00:00 2001
From: Remy Willems <rwillems@amazon.com>
Date: Wed, 25 Sep 2024 15:09:18 +0200
Subject: [PATCH 9/9] Format atg

---
 Source/Core/AST/BigBlocksResolutionContext.cs | 1 +
 Source/Core/BoogiePL.atg                      | 8 ++++----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Source/Core/AST/BigBlocksResolutionContext.cs b/Source/Core/AST/BigBlocksResolutionContext.cs
index dcce234f9..2d195907e 100644
--- a/Source/Core/AST/BigBlocksResolutionContext.cs
+++ b/Source/Core/AST/BigBlocksResolutionContext.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
+using System.Linq;
 
 namespace Microsoft.Boogie;
 
diff --git a/Source/Core/BoogiePL.atg b/Source/Core/BoogiePL.atg
index 0cdf885ff..569365335 100644
--- a/Source/Core/BoogiePL.atg
+++ b/Source/Core/BoogiePL.atg
@@ -1153,10 +1153,10 @@ LabelOrCmd<out Cmd c, out IToken label>
     { Attribute<ref kv> }
     Proposition<out e>    (. c = new AssertCmd(x, e, kv); .)
     ";"
-  | "check"              (. x = t; .)
-      { Attribute<ref kv> }
-      Proposition<out e>    (. c = new AssertCmd(x, e, kv) { Remember = false }; .)
-      ";"
+  | "check"               (. x = t; .)
+    { Attribute<ref kv> }
+    Proposition<out e>    (. c = new AssertCmd(x, e, kv) { Remember = false }; .)
+    ";"
   | "assume"              (. x = t; .)
     { Attribute<ref kv> }
     Proposition<out e>    (. c = new AssumeCmd(x, e, kv); .)