Fixes

Source/AbstractInterpretation/NativeLattice.cs

@@ -379,6 +379,8 @@ NativeLattice.Element Step(NativeLattice lattice, Cmd cmd, NativeLattice.Element
       }
       else if (cmd is HideRevealCmd) {
         // skip
+      } else if (cmd is ChangeScope) {
+        // skip
       }
       else
       {

Source/Core/AST/HideRevealCmd.cs

@@ -29,6 +29,9 @@ public override void Typecheck(TypecheckingContext tc)
 
   public override void Emit(TokenTextWriter stream, int level)
   {
+    stream.Write(this, level, Hide ? "hide " : "reveal ");
+    stream.Write(this, level, Function == null ? "*" : Function.Name);
+    stream.WriteLine(";");
   }
 
   public override void AddAssignedVariables(List<Variable> vars)

Source/Graph/Graph.cs

@@ -1182,18 +1182,22 @@ public static IEnumerable<object> FindReachableNodesInGraphWithMergeNodes(
           continue;
         }
 
-
+        IReadOnlyList<object> parents; 
         if (node is IEnumerable<object> objects) {
           if (!visitedEdges.IsSupersetOf(objects)) {
             continue;
           }
+
+          parents = objects.ToList();
+        } else {
+          parents = new[] { node };
         }
         visitedEdges.Add(node);
 
         var outgoing = edges.GetValueOrDefault(node) ?? new List<object>();
         foreach (var child in outgoing)
         {
-          if (visitChild != null && !visitChild(node, child))
+          if (visitChild != null && parents.Any(p => !visitChild(p, child)))
           {
             continue;
           }

Source/VCGeneration/Prune/DataflowAnalysis.cs

@@ -3,7 +3,7 @@
 using System.Linq;
 
 abstract class DataflowAnalysis<TNode, TState> {
-  protected readonly Dictionary<TNode, TState> states;
+  protected readonly Dictionary<TNode, TState> states = new();
   protected readonly Dictionary<TNode, TState> inStates = new();
   private readonly Func<TNode, IEnumerable<TNode>> getNext;
   private readonly Func<TNode, IEnumerable<TNode>> getPrevious;
@@ -15,7 +15,6 @@ protected DataflowAnalysis(IReadOnlyList<TNode> roots,
     this.getNext = getNext;
     this.getPrevious = getPrevious;
     this.roots = roots;
-    states = roots.ToDictionary(n => n, n => Empty);
   }
 
   public IReadOnlyDictionary<TNode, TState> States => states;