Dafny: Implemented abstract modules

15 files changed, 1295 insertions, 794 deletions

diff --git a/Binaries/DafnyPrelude.bpl b/Binaries/DafnyPrelude.bpl
index fef8fe1f..53d0b471 100644
--- a/Binaries/DafnyPrelude.bpl
+++ b/Binaries/DafnyPrelude.bpl
@@ -500,6 +500,13 @@ axiom (forall f: Field BoxType, i: int :: { MultiIndexField(f,i) }
 

 function DeclType<T>(Field T): ClassName;

 

+type NameFamily;

+function DeclName<T>(Field T): NameFamily;

+function FieldOfDecl<alpha>(ClassName, NameFamily): Field alpha;

+axiom (forall<T> cl : ClassName, nm: NameFamily :: 

+   {FieldOfDecl(cl, nm): Field T}

+   DeclType(FieldOfDecl(cl, nm): Field T) == cl && DeclName(FieldOfDecl(cl, nm): Field T) == nm);

+

 // ---------------------------------------------------------------

 // -- Allocatedness ----------------------------------------------

 // ---------------------------------------------------------------

diff --git a/Source/Dafny/Compiler.cs b/Source/Dafny/Compiler.cs
index e72c04dd..7f48e551 100644
--- a/Source/Dafny/Compiler.cs
+++ b/Source/Dafny/Compiler.cs
@@ -66,7 +66,7 @@ namespace Microsoft.Dafny {
       ReadRuntimeSystem();

       CompileBuiltIns(program.BuiltIns);

 

-      foreach (ModuleDecl m in program.Modules) {

+      foreach (ModuleDefinition m in program.Modules) {

         if (m.IsGhost) {

           // the purpose of a ghost module is to skip compilation

           continue;

@@ -91,7 +91,7 @@ namespace Microsoft.Dafny {
             wr.WriteLine(" { }");

             CompileDatatypeConstructors(dt, indent);

             CompileDatatypeStruct(dt, indent);

-          } else {

+          } else if (d is ClassDecl) {

             ClassDecl cl = (ClassDecl)d;

             Indent(indent);

             wr.Write("public class @{0}", cl.CompileName);

@@ -101,7 +101,9 @@ namespace Microsoft.Dafny {
             wr.WriteLine(" {");

             CompileClassMembers(cl, indent+IndentAmount);

             Indent(indent);  wr.WriteLine("}");

-          }

+          } else if (d is ModuleDecl) {

+            // nop

+          } else { Contract.Assert(false); }

         }

         if (!m.IsDefaultModule) {

           wr.WriteLine("}} // end of namespace {0}", m.CompileName);

diff --git a/Source/Dafny/Dafny.atg b/Source/Dafny/Dafny.atg
index 4b76f9b4..ca8f934e 100644
--- a/Source/Dafny/Dafny.atg
+++ b/Source/Dafny/Dafny.atg
@@ -71,7 +71,7 @@ public static int Parse (string/*!*/ s, string/*!*/ filename, ModuleDecl module,
   Contract.Requires(filename != null);

   Contract.Requires(module != null);

   Contract.Requires(errors != null);

-  ModuleDecl oldModule = theModule;

+  var oldModule = theModule;

   theModule = module;

   BuiltIns oldBuiltIns = builtIns;

   theBuiltIns = builtIns;

@@ -132,9 +132,9 @@ PRODUCTIONS
 Dafny

 = (. ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at;

      List<MemberDecl/*!*/> membersDefaultClass = new List<MemberDecl/*!*/>();

-     SubModuleDecl submodule;

+     ModuleDecl submodule;

      // to support multiple files, create a default module only if theModule is null

-     DefaultModuleDecl defaultModule = theModule as DefaultModuleDecl;

+     DefaultModuleDecl defaultModule = (DefaultModuleDecl)((LiteralModuleDecl)theModule).ModuleDef;

      // theModule should be a DefaultModuleDecl (actually, the singular DefaultModuleDecl)

      Contract.Assert(defaultModule != null);

      bool isGhost;

@@ -163,23 +163,22 @@ Dafny
      } .)

   EOF

   .

-SubModuleDecl<ModuleDecl parent, bool isOverallModuleGhost, out SubModuleDecl submodule>

+SubModuleDecl<ModuleDefinition parent, bool isOverallModuleGhost, out ModuleDecl submodule>

 = (. ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at;

      Attributes attrs = null;  IToken/*!*/ id; 

      List<MemberDecl/*!*/> namedModuleDefaultClassMembers = new List<MemberDecl>();;

-     IToken idRefined = null;

-     List<string/*!*/> theImports = new List<string/*!*/>();

+     List<IToken> idRefined = null, idPath = null;

      bool isGhost = false;

-     ModuleDecl module;

-     SubModuleDecl sm;

+     ModuleDefinition module;

+     ModuleDecl sm;

+     submodule = null; // appease compiler

   .)

-     "module"

-      { Attribute<ref attrs> }

-      NoUSIdent<out id>                        (. .)

-      [ "refines" Ident<out idRefined> ]

-      [ "imports" Idents<theImports> ]     (. module = new ModuleDecl(id, id.val, isOverallModuleGhost, idRefined == null ? null : idRefined.val, theImports, attrs);

-                                              parent.Dependencies.Add(module); .)

-      "{"                                  (. module.BodyStartTok = t; .)

+    "module"

+    { Attribute<ref attrs> }

+    NoUSIdent<out id>                          

+    ((

+      [ "refines" QualifiedName<out idRefined> ] (. module = new ModuleDefinition(id, id.val, isOverallModuleGhost, false, idRefined == null ? null : idRefined, attrs); .)

+       "{"                                       (. module.BodyStartTok = t; .)

         { (. isGhost = false; .)

           [ "ghost"  (. isGhost = true; .) ]

             ( SubModuleDecl<module, isGhost, out sm>        (. module.TopLevelDecls.Add(sm); .)

@@ -194,10 +193,22 @@ SubModuleDecl<ModuleDecl parent, bool isOverallModuleGhost, out SubModuleDecl su
         }

       "}"                                  (. module.BodyEndTok = t;

                                               module.TopLevelDecls.Add(new DefaultClassDecl(module, namedModuleDefaultClassMembers));

-                                              submodule = new SubModuleDecl(module, parent); .)

+                                              submodule = new LiteralModuleDecl(module, parent); .)

+     ) | 

+      "=" QualifiedName<out idPath> ";" (. submodule = new AliasModuleDecl(idPath, id, parent); .)

+       |

+      "as" QualifiedName<out idPath> ";" (.submodule = new AbstractModuleDecl(idPath, id, parent); .)

+    )

 .

 

-ClassDecl<ModuleDecl/*!*/ module, out ClassDecl/*!*/ c>

+QualifiedName<.out List<IToken> ids.>

+= (. IToken id; ids = new List<IToken>(); .)

+  Ident<out id>                            (. ids.Add(id); .)

+  { "." Ident<out id>                      (. ids.Add(id); .)

+  }

+  .

+

+ClassDecl<ModuleDefinition/*!*/ module, out ClassDecl/*!*/ c>

 = (. Contract.Requires(module != null);

      Contract.Ensures(Contract.ValueAtReturn(out c) != null);

      IToken/*!*/ id;

@@ -235,7 +246,7 @@ ClassMemberDecl<.List<MemberDecl/*!*/>/*!*/ mm, bool isAlreadyGhost, bool allowC
   | MethodDecl<mmod, allowConstructors, out m>  (. mm.Add(m); .)

   )

   .

-DatatypeDecl<ModuleDecl/*!*/ module, out DatatypeDecl/*!*/ dt>

+DatatypeDecl<ModuleDefinition/*!*/ module, out DatatypeDecl/*!*/ dt>

 = (. Contract.Requires(module != null);

      Contract.Ensures(Contract.ValueAtReturn(out dt)!=null);

      IToken/*!*/ id;

@@ -291,7 +302,7 @@ FieldDecl<.MemberModifiers mmod, List<MemberDecl/*!*/>/*!*/ mm.>
   }

   SYNC ";"

   .

-ArbitraryTypeDecl<ModuleDecl/*!*/ module, out ArbitraryTypeDecl at>

+ArbitraryTypeDecl<ModuleDefinition/*!*/ module, out ArbitraryTypeDecl at>

 = (. IToken/*!*/ id;

      Attributes attrs = null;

   .)

@@ -1629,12 +1640,6 @@ AttributeArg<out Attributes.Argument/*!*/ arg>
   )

   .

 /*------------------------------------------------------------------------*/

-Idents<.List<string/*!*/>/*!*/ ids.>

-= (. IToken/*!*/ id; .)

-  Ident<out id>                            (. ids.Add(id.val); .)

-  { "," Ident<out id>                      (. ids.Add(id.val); .)

-  }

-  .

 Ident<out IToken/*!*/ x>

 = (. Contract.Ensures(Contract.ValueAtReturn(out x) != null); .)

   ident            (. x = t; .)

diff --git a/Source/Dafny/DafnyAst.cs b/Source/Dafny/DafnyAst.cs
index dc012b32..19bb8b72 100644
--- a/Source/Dafny/DafnyAst.cs
+++ b/Source/Dafny/DafnyAst.cs
@@ -19,24 +19,27 @@ namespace Microsoft.Dafny {
     }

 

     public readonly string Name;

-    public List<ModuleDecl/*!*/>/*!*/ Modules; // filled in during resolution.

+    public List<ModuleDefinition/*!*/>/*!*/ Modules; // filled in during resolution.

                                                // Resolution essentially flattens the module heirarchy, for

                                                // purposes of translation and compilation.

     public readonly ModuleDecl DefaultModule;

+    public readonly ModuleDefinition DefaultModuleDef;

     public readonly BuiltIns BuiltIns;

     public Program(string name, [Captured] ModuleDecl module, [Captured] BuiltIns builtIns) {

       Contract.Requires(name != null);

       Contract.Requires(module != null);

+      Contract.Requires(module is LiteralModuleDecl);

       Name = name;

       DefaultModule = module;

+      DefaultModuleDef = (DefaultModuleDecl)((LiteralModuleDecl)module).ModuleDef;

       BuiltIns = builtIns;

-      Modules = new List<ModuleDecl>();

+      Modules = new List<ModuleDefinition>();

     }

   }

 

   public class BuiltIns

   {

-    public readonly ModuleDecl SystemModule = new ModuleDecl(Token.NoToken, "_System", false, null, new List<string>(), null);

+    public readonly ModuleDefinition SystemModule = new ModuleDefinition(Token.NoToken, "_System", false, false, null, null);

     Dictionary<int, ClassDecl/*!*/> arrayTypeDecls = new Dictionary<int, ClassDecl>();

 

     public BuiltIns() {

@@ -734,46 +737,100 @@ namespace Microsoft.Dafny {
     }

   }

 

-  public class SubModuleDecl : TopLevelDecl {

-    public readonly ModuleDecl SubModule;

-    public SubModuleDecl(ModuleDecl submodule, ModuleDecl parent)

-      : base(submodule.tok, submodule.Name, parent, new List<TypeParameter>(), submodule.Attributes) {

-        SubModule = submodule;

+  // Represents a submodule declartion at module level scope

+  abstract public class ModuleDecl : TopLevelDecl

+  {

+    public ModuleSignature Signature; // filled in by resolution, in topological order.

+    public int Height;

+    public ModuleDecl(IToken tok, string name, ModuleDefinition parent)

+      : base(tok, name, parent, new List<TypeParameter>(), null) {

+        Height = -1;

+        Signature = null;

+    }

+  }

+  // Represents module X { ... }

+  public class LiteralModuleDecl : ModuleDecl

+  {

+    public readonly ModuleDefinition ModuleDef;

+    public LiteralModuleDecl(ModuleDefinition module, ModuleDefinition parent)

+      : base(module.tok, module.Name, parent) {

+      ModuleDef = module;

     }

   }

-  public class ModuleDecl : Declaration {

-    public readonly string RefinementBaseName;  // null if no refinement base

-    public ModuleDecl RefinementBase;  // filled in during resolution (null if no refinement base)

-    public readonly List<string/*!*/>/*!*/ ImportNames;  // contains no duplicates

-    public readonly List<ModuleDecl>/*!*/ Dependencies;  // filled in during parsing. contains submodules dependencies.

-    public readonly List<ModuleDecl>/*!*/ Imports = new List<ModuleDecl>();  // filled in during resolution, contains no duplicates

+  // Represents "module name = path;", where name is a identifier and path is a possibly qualified name.

+  public class AliasModuleDecl : ModuleDecl

+  {

+    public ModuleDecl ModuleReference; // should refer to another declaration somewhere. NOTE: cyclicity is possible, and should

+                                       // be detected and warned.

+    public readonly List<IToken> Path; // generated by the parser, this is looked up

+    public ModuleDecl Root;            // the moduleDecl that Path[0] refers to.

+    public AliasModuleDecl(List<IToken> path, IToken name, ModuleDefinition parent)

+      : base(name, name.val, parent) {

+       Contract.Requires(path != null && path.Count > 0);

+       Path = path;

+       ModuleReference = null;

+    }

+  }

+  // Represents "module name as path;", where name is a identifier and path is a possibly qualified name.

+  public class AbstractModuleDecl : ModuleDecl

+  {

+    public ModuleDecl Root;

+    public readonly List<IToken> Path;

+    public AbstractModuleDecl(List<IToken> path, IToken name, ModuleDefinition parent)

+      : base(name, name.val, parent) {

+      Path = path;

+      Root = null;

+    }

+  }

+

+  public class ModuleSignature {

+    

+    public readonly Dictionary<string, TopLevelDecl> TopLevels = new Dictionary<string, TopLevelDecl>();

+    public readonly Dictionary<string, Tuple<DatatypeCtor, bool>> Ctors = new Dictionary<string, Tuple<DatatypeCtor, bool>>();

+    public ModuleDefinition ModuleDef; // Note: this is null if this signature does not correspond to a specific definition (i.e.

+                                       // it is abstract). Otherwise, it points to that definition.

+    public ModuleSignature() {}

+

+    public bool FindSubmodule(string name, out ModuleSignature pp) {

+      TopLevelDecl top;

+      pp = null;

+      if (TopLevels.TryGetValue(name, out top)) {

+        if (top is ModuleDecl) {

+          pp = ((ModuleDecl)top).Signature;

+          return true;

+        } else return false;

+      } else return false;

+    }

+    

+      

+  }

+  public class ModuleDefinition : Declaration {

+    public readonly List<IToken> RefinementBaseName;  // null if no refinement base

+    public ModuleDecl RefinementBaseRoot; // filled in early during resolution, corresponds to RefinementBaseName[0]

+    public ModuleDefinition RefinementBase;  // filled in during resolution (null if no refinement base)

+    

     public readonly List<TopLevelDecl/*!*/> TopLevelDecls = new List<TopLevelDecl/*!*/>();  // filled in by the parser; readonly after that

+    public Resolver.ModuleBindings Bindings;

     public readonly Graph<MemberDecl/*!*/> CallGraph = new Graph<MemberDecl/*!*/>();  // filled in during resolution

     public int Height;  // height in the topological sorting of modules; filled in during resolution

     public readonly bool IsGhost;

+    public readonly bool IsAbstract; // True iff this module represents an abstract interface

 

     [ContractInvariantMethod]

     void ObjectInvariant() {

-      Contract.Invariant(cce.NonNullElements(ImportNames));

       Contract.Invariant(cce.NonNullElements(TopLevelDecls));

       Contract.Invariant(CallGraph != null);

     }

 

-    public ModuleDecl(IToken tok, string name, bool isGhost, string refinementBase, [Captured] List<string/*!*/>/*!*/ imports, Attributes attributes)

+    public ModuleDefinition(IToken tok, string name, bool isGhost, bool isAbstract, List<IToken> refinementBase,  Attributes attributes)

       : base(tok, name, attributes) {

       Contract.Requires(tok != null);

       Contract.Requires(name != null);

-      Contract.Requires(cce.NonNullElements(imports));

       RefinementBaseName = refinementBase;

-      // set "ImportNames" to "imports" minus any duplicates

-      ImportNames = new List<string>();

-      Dependencies = new List<ModuleDecl>();

-      foreach (var nm in imports) {

-        if (!ImportNames.Contains(nm)) {

-          ImportNames.Add(nm);

-        }

-      }

       IsGhost = isGhost;

+      IsAbstract = isAbstract;

+      RefinementBaseRoot = null;

+      RefinementBase = null;

     }

     public virtual bool IsDefaultModule {

       get {

@@ -784,20 +841,15 @@ namespace Microsoft.Dafny {
     new public string CompileName {

       get {

         if (compileName == null) {

-          compileName = NonglobalVariable.CompilerizeName(Name) + "_" + Height.ToString();

+          compileName = "_" + Height.ToString() + "_" + NonglobalVariable.CompilerizeName(Name);

         }

         return compileName;

       }

     }

-    public string UniqueName {

-      get {

-        return Name + "_" + Height.ToString();

-      }

-    }

   }

 

-  public class DefaultModuleDecl : ModuleDecl {

-    public DefaultModuleDecl() : base(Token.NoToken, "_default", false, null, new List<string/*!*/>(), null) {

+  public class DefaultModuleDecl : ModuleDefinition {

+    public DefaultModuleDecl() : base(Token.NoToken, "_module", false, false, null, null) {

     }

     public override bool IsDefaultModule {

       get {

@@ -807,7 +859,7 @@ namespace Microsoft.Dafny {
   }

 

   public abstract class TopLevelDecl : Declaration, TypeParameter.ParentType {

-    public readonly ModuleDecl Module;

+    public readonly ModuleDefinition Module;

     public readonly List<TypeParameter/*!*/>/*!*/ TypeArgs;

     [ContractInvariantMethod]

     void ObjectInvariant() {

@@ -815,7 +867,7 @@ namespace Microsoft.Dafny {
       Contract.Invariant(cce.NonNullElements(TypeArgs));

     }

 

-    public TopLevelDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs, Attributes attributes)

+    public TopLevelDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs, Attributes attributes)

       : base(tok, name, attributes) {

       Contract.Requires(tok != null);

       Contract.Requires(name != null);

@@ -845,7 +897,7 @@ namespace Microsoft.Dafny {
       Contract.Invariant(cce.NonNullElements(Members));

     }

 

-    public ClassDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module,

+    public ClassDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module,

       List<TypeParameter/*!*/>/*!*/ typeArgs, [Captured] List<MemberDecl/*!*/>/*!*/ members, Attributes attributes)

       : base(tok, name, module, typeArgs, attributes) {

       Contract.Requires(tok != null);

@@ -865,7 +917,7 @@ namespace Microsoft.Dafny {
   }

 

   public class DefaultClassDecl : ClassDecl {

-    public DefaultClassDecl(ModuleDecl/*!*/ module, [Captured] List<MemberDecl/*!*/>/*!*/ members)

+    public DefaultClassDecl(ModuleDefinition/*!*/ module, [Captured] List<MemberDecl/*!*/>/*!*/ members)

       : base(Token.NoToken, "_default", module, new List<TypeParameter/*!*/>(), members, null) {

       Contract.Requires(module != null);

       Contract.Requires(cce.NonNullElements(members));

@@ -879,7 +931,7 @@ namespace Microsoft.Dafny {
 

   public class ArrayClassDecl : ClassDecl {

     public readonly int Dims;

-    public ArrayClassDecl(int dims, ModuleDecl module)

+    public ArrayClassDecl(int dims, ModuleDefinition module)

     : base(Token.NoToken, BuiltIns.ArrayClassName(dims), module,

       new List<TypeParameter>(new TypeParameter[]{new TypeParameter(Token.NoToken, "arg")}),

       new List<MemberDecl>(), null)

@@ -899,7 +951,7 @@ namespace Microsoft.Dafny {
       Contract.Invariant(1 <= Ctors.Count);

     }

 

-    public DatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

+    public DatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

       [Captured] List<DatatypeCtor/*!*/>/*!*/ ctors, Attributes attributes)

       : base(tok, name, module, typeArgs, attributes) {

       Contract.Requires(tok != null);

@@ -917,7 +969,7 @@ namespace Microsoft.Dafny {
     public DatatypeCtor DefaultCtor;  // set during resolution

     public bool[] TypeParametersUsedInConstructionByDefaultCtor;  // set during resolution; has same length as

 

-    public IndDatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

+    public IndDatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

       [Captured] List<DatatypeCtor/*!*/>/*!*/ ctors, Attributes attributes)

       : base(tok, name, module, typeArgs, ctors, attributes) {

       Contract.Requires(tok != null);

@@ -931,7 +983,7 @@ namespace Microsoft.Dafny {
 

   public class CoDatatypeDecl : DatatypeDecl

   {

-    public CoDatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

+    public CoDatatypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module, List<TypeParameter/*!*/>/*!*/ typeArgs,

       [Captured] List<DatatypeCtor/*!*/>/*!*/ ctors, Attributes attributes)

       : base(tok, name, module, typeArgs, ctors, attributes) {

       Contract.Requires(tok != null);

@@ -1075,7 +1127,7 @@ namespace Microsoft.Dafny {
       Contract.Invariant(TheType != null && Name == TheType.Name);

     }

 

-    public ArbitraryTypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDecl/*!*/ module, Attributes attributes)

+    public ArbitraryTypeDecl(IToken/*!*/ tok, string/*!*/ name, ModuleDefinition/*!*/ module, Attributes attributes)

       : base(tok, name, module, new List<TypeParameter>(), attributes) {

       Contract.Requires(tok != null);

       Contract.Requires(name != null);

diff --git a/Source/Dafny/DafnyMain.cs b/Source/Dafny/DafnyMain.cs
index 90c2de44..6091e522 100644
--- a/Source/Dafny/DafnyMain.cs
+++ b/Source/Dafny/DafnyMain.cs
@@ -20,7 +20,7 @@ namespace Microsoft.Dafny {
       Contract.Requires(programName != null);

       Contract.Requires(fileNames != null);

       program = null;

-      ModuleDecl module = new DefaultModuleDecl();

+      ModuleDecl module = new LiteralModuleDecl(new DefaultModuleDecl(), null);

       BuiltIns builtIns = new BuiltIns();

       foreach (string dafnyFileName in fileNames){

         Contract.Assert(dafnyFileName != null);

diff --git a/Source/Dafny/DafnyPipeline.csproj b/Source/Dafny/DafnyPipeline.csproj
index cf2b51eb..14ff3348 100644
--- a/Source/Dafny/DafnyPipeline.csproj
+++ b/Source/Dafny/DafnyPipeline.csproj
@@ -151,6 +151,7 @@
     <Reference Include="System.Xml" />

   </ItemGroup>

   <ItemGroup>

+    <Compile Include="Util.cs" />

     <Compile Include="Compiler.cs" />

     <Compile Include="DafnyAst.cs" />

     <Compile Include="DafnyMain.cs" />

diff --git a/Source/Dafny/Parser.cs b/Source/Dafny/Parser.cs
index 3f58c1db..931970ca 100644
--- a/Source/Dafny/Parser.cs
+++ b/Source/Dafny/Parser.cs
@@ -91,7 +91,7 @@ public static int Parse (string/*!*/ s, string/*!*/ filename, ModuleDecl module,
   Contract.Requires(filename != null);

   Contract.Requires(module != null);

   Contract.Requires(errors != null);

-  ModuleDecl oldModule = theModule;

+  var oldModule = theModule;

   theModule = module;

   BuiltIns oldBuiltIns = builtIns;

   theBuiltIns = builtIns;

@@ -182,9 +182,9 @@ bool IsAttribute() {
 	void Dafny() {

 		ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at;

 		List<MemberDecl/*!*/> membersDefaultClass = new List<MemberDecl/*!*/>();

-		SubModuleDecl submodule;

+		ModuleDecl submodule;

 		// to support multiple files, create a default module only if theModule is null

-		DefaultModuleDecl defaultModule = theModule as DefaultModuleDecl;

+		DefaultModuleDecl defaultModule = (DefaultModuleDecl)((LiteralModuleDecl)theModule).ModuleDef;

 		// theModule should be a DefaultModuleDecl (actually, the singular DefaultModuleDecl)

 		Contract.Assert(defaultModule != null);

 		bool isGhost;

@@ -198,15 +198,15 @@ bool IsAttribute() {
 			if (la.kind == 9) {

 				SubModuleDecl(defaultModule, isGhost, out submodule);

 				defaultModule.TopLevelDecls.Add(submodule); 

-			} else if (la.kind == 12) {

+			} else if (la.kind == 15) {

 				if (isGhost) { SemErr(t, "a class is not allowed to be declared as 'ghost'"); } 

 				ClassDecl(defaultModule, out c);

 				defaultModule.TopLevelDecls.Add(c); 

-			} else if (la.kind == 14 || la.kind == 15) {

+			} else if (la.kind == 17 || la.kind == 18) {

 				if (isGhost) { SemErr(t, "a datatype/codatatype is not allowed to be declared as 'ghost'"); } 

 				DatatypeDecl(defaultModule, out dt);

 				defaultModule.TopLevelDecls.Add(dt); 

-			} else if (la.kind == 21) {

+			} else if (la.kind == 22) {

 				if (isGhost) { SemErr(t, "a type is not allowed to be declared as 'ghost'"); } 

 				ArbitraryTypeDecl(defaultModule, out at);

 				defaultModule.TopLevelDecls.Add(at); 

@@ -224,66 +224,72 @@ bool IsAttribute() {
 		Expect(0);

 	}

 

-	void SubModuleDecl(ModuleDecl parent, bool isOverallModuleGhost, out SubModuleDecl submodule) {

+	void SubModuleDecl(ModuleDefinition parent, bool isOverallModuleGhost, out ModuleDecl submodule) {

 		ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at;

 		Attributes attrs = null;  IToken/*!*/ id; 

 		List<MemberDecl/*!*/> namedModuleDefaultClassMembers = new List<MemberDecl>();;

-		IToken idRefined = null;

-		List<string/*!*/> theImports = new List<string/*!*/>();

+		List<IToken> idRefined = null, idPath = null;

 		bool isGhost = false;

-		ModuleDecl module;

-		SubModuleDecl sm;

+		ModuleDefinition module;

+		ModuleDecl sm;

+		submodule = null; // appease compiler

 		

 		Expect(9);

 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

-		

-		if (la.kind == 10) {

-			Get();

-			Ident(out idRefined);

-		}

-		if (la.kind == 11) {

-			Get();

-			Idents(theImports);

-		}

-		module = new ModuleDecl(id, id.val, isOverallModuleGhost, idRefined == null ? null : idRefined.val, theImports, attrs);

-		parent.Dependencies.Add(module); 

-		Expect(6);

-		module.BodyStartTok = t; 

-		while (StartOf(1)) {

-			isGhost = false; 

-			if (la.kind == 8) {

+		if (la.kind == 6 || la.kind == 10) {

+			if (la.kind == 10) {

 				Get();

-				isGhost = true; 

+				QualifiedName(out idRefined);

 			}

-			if (la.kind == 9) {

-				SubModuleDecl(module, isGhost, out sm);

-				module.TopLevelDecls.Add(sm); 

-			} else if (la.kind == 12) {

-				if (isGhost) { SemErr(t, "a class is not allowed to be declared as 'ghost'"); } 

-				ClassDecl(module, out c);

-				module.TopLevelDecls.Add(c); 

-			} else if (la.kind == 14 || la.kind == 15) {

-				if (isGhost) { SemErr(t, "a datatype/codatatype is not allowed to be declared as 'ghost'"); } 

-				DatatypeDecl(module, out dt);

-				module.TopLevelDecls.Add(dt); 

-			} else if (la.kind == 21) {

-				if (isGhost) { SemErr(t, "a type is not allowed to be declared as 'ghost'"); } 

-				ArbitraryTypeDecl(module, out at);

-				module.TopLevelDecls.Add(at); 

-			} else if (StartOf(2)) {

-				ClassMemberDecl(namedModuleDefaultClassMembers, isGhost, false);

-			} else SynErr(109);

-		}

-		Expect(7);

-		module.BodyEndTok = t;

-		module.TopLevelDecls.Add(new DefaultClassDecl(module, namedModuleDefaultClassMembers));

-		submodule = new SubModuleDecl(module, parent); 

+			module = new ModuleDefinition(id, id.val, isOverallModuleGhost, false, idRefined == null ? null : idRefined, attrs); 

+			Expect(6);

+			module.BodyStartTok = t; 

+			while (StartOf(1)) {

+				isGhost = false; 

+				if (la.kind == 8) {

+					Get();

+					isGhost = true; 

+				}

+				if (la.kind == 9) {

+					SubModuleDecl(module, isGhost, out sm);

+					module.TopLevelDecls.Add(sm); 

+				} else if (la.kind == 15) {

+					if (isGhost) { SemErr(t, "a class is not allowed to be declared as 'ghost'"); } 

+					ClassDecl(module, out c);

+					module.TopLevelDecls.Add(c); 

+				} else if (la.kind == 17 || la.kind == 18) {

+					if (isGhost) { SemErr(t, "a datatype/codatatype is not allowed to be declared as 'ghost'"); } 

+					DatatypeDecl(module, out dt);

+					module.TopLevelDecls.Add(dt); 

+				} else if (la.kind == 22) {

+					if (isGhost) { SemErr(t, "a type is not allowed to be declared as 'ghost'"); } 

+					ArbitraryTypeDecl(module, out at);

+					module.TopLevelDecls.Add(at); 

+				} else if (StartOf(2)) {

+					ClassMemberDecl(namedModuleDefaultClassMembers, isGhost, false);

+				} else SynErr(109);

+			}

+			Expect(7);

+			module.BodyEndTok = t;

+			module.TopLevelDecls.Add(new DefaultClassDecl(module, namedModuleDefaultClassMembers));

+			submodule = new LiteralModuleDecl(module, parent); 

+		} else if (la.kind == 11) {

+			Get();

+			QualifiedName(out idPath);

+			Expect(12);

+			submodule = new AliasModuleDecl(idPath, id, parent); 

+		} else if (la.kind == 13) {

+			Get();

+			QualifiedName(out idPath);

+			Expect(12);

+			submodule = new AbstractModuleDecl(idPath, id, parent); 

+		} else SynErr(110);

 	}

 

-	void ClassDecl(ModuleDecl/*!*/ module, out ClassDecl/*!*/ c) {

+	void ClassDecl(ModuleDefinition/*!*/ module, out ClassDecl/*!*/ c) {

 		Contract.Requires(module != null);

 		Contract.Ensures(Contract.ValueAtReturn(out c) != null);

 		IToken/*!*/ id;

@@ -292,13 +298,13 @@ bool IsAttribute() {
 		List<MemberDecl/*!*/> members = new List<MemberDecl/*!*/>();

 		IToken bodyStart;

 		

-		while (!(la.kind == 0 || la.kind == 12)) {SynErr(110); Get();}

-		Expect(12);

+		while (!(la.kind == 0 || la.kind == 15)) {SynErr(111); Get();}

+		Expect(15);

 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

-		if (la.kind == 22) {

+		if (la.kind == 23) {

 			GenericParameters(typeArgs);

 		}

 		Expect(6);

@@ -313,7 +319,7 @@ bool IsAttribute() {
 		

 	}

 

-	void DatatypeDecl(ModuleDecl/*!*/ module, out DatatypeDecl/*!*/ dt) {

+	void DatatypeDecl(ModuleDefinition/*!*/ module, out DatatypeDecl/*!*/ dt) {

 		Contract.Requires(module != null);

 		Contract.Ensures(Contract.ValueAtReturn(out dt)!=null);

 		IToken/*!*/ id;

@@ -323,29 +329,29 @@ bool IsAttribute() {
 		IToken bodyStart = Token.NoToken;  // dummy assignment

 		bool co = false;

 		

-		while (!(la.kind == 0 || la.kind == 14 || la.kind == 15)) {SynErr(111); Get();}

-		if (la.kind == 14) {

+		while (!(la.kind == 0 || la.kind == 17 || la.kind == 18)) {SynErr(112); Get();}

+		if (la.kind == 17) {

 			Get();

-		} else if (la.kind == 15) {

+		} else if (la.kind == 18) {

 			Get();

 			co = true; 

-		} else SynErr(112);

+		} else SynErr(113);

 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

-		if (la.kind == 22) {

+		if (la.kind == 23) {

 			GenericParameters(typeArgs);

 		}

-		Expect(16);

+		Expect(11);

 		bodyStart = t; 

 		DatatypeMemberDecl(ctors);

-		while (la.kind == 17) {

+		while (la.kind == 19) {

 			Get();

 			DatatypeMemberDecl(ctors);

 		}

-		while (!(la.kind == 0 || la.kind == 18)) {SynErr(113); Get();}

-		Expect(18);

+		while (!(la.kind == 0 || la.kind == 12)) {SynErr(114); Get();}

+		Expect(12);

 		if (co) {

 		 dt = new CoDatatypeDecl(id, id.val, module, typeArgs, ctors, attrs);

 		} else {

@@ -356,18 +362,18 @@ bool IsAttribute() {
 		

 	}

 

-	void ArbitraryTypeDecl(ModuleDecl/*!*/ module, out ArbitraryTypeDecl at) {

+	void ArbitraryTypeDecl(ModuleDefinition/*!*/ module, out ArbitraryTypeDecl at) {

 		IToken/*!*/ id;

 		Attributes attrs = null;

 		

-		Expect(21);

+		Expect(22);

 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

 		at = new ArbitraryTypeDecl(id, id.val, module, attrs); 

-		while (!(la.kind == 0 || la.kind == 18)) {SynErr(114); Get();}

-		Expect(18);

+		while (!(la.kind == 0 || la.kind == 12)) {SynErr(115); Get();}

+		Expect(12);

 	}

 

 	void ClassMemberDecl(List<MemberDecl/*!*/>/*!*/ mm, bool isAlreadyGhost, bool allowConstructors) {

@@ -377,7 +383,7 @@ bool IsAttribute() {
 		MemberModifiers mmod = new MemberModifiers();

 		mmod.IsGhost = isAlreadyGhost;

 		

-		while (la.kind == 8 || la.kind == 13) {

+		while (la.kind == 8 || la.kind == 16) {

 			if (la.kind == 8) {

 				Get();

 				mmod.IsGhost = true; 

@@ -386,15 +392,15 @@ bool IsAttribute() {
 				mmod.IsStatic = true; 

 			}

 		}

-		if (la.kind == 19) {

+		if (la.kind == 20) {

 			FieldDecl(mmod, mm);

 		} else if (la.kind == 44 || la.kind == 45) {

 			FunctionDecl(mmod, out f);

 			mm.Add(f); 

-		} else if (la.kind == 24 || la.kind == 25) {

+		} else if (la.kind == 25 || la.kind == 26) {

 			MethodDecl(mmod, allowConstructors, out m);

 			mm.Add(m); 

-		} else SynErr(115);

+		} else SynErr(116);

 	}

 

 	void Attribute(ref Attributes attrs) {

@@ -413,35 +419,35 @@ bool IsAttribute() {
 		

 	}

 

-	void Ident(out IToken/*!*/ x) {

-		Contract.Ensures(Contract.ValueAtReturn(out x) != null); 

-		Expect(1);

-		x = t; 

-	}

-

-	void Idents(List<string/*!*/>/*!*/ ids) {

-		IToken/*!*/ id; 

+	void QualifiedName(out List<IToken> ids) {

+		IToken id; ids = new List<IToken>(); 

 		Ident(out id);

-		ids.Add(id.val); 

-		while (la.kind == 20) {

+		ids.Add(id); 

+		while (la.kind == 14) {

 			Get();

 			Ident(out id);

-			ids.Add(id.val); 

+			ids.Add(id); 

 		}

 	}

 

+	void Ident(out IToken/*!*/ x) {

+		Contract.Ensures(Contract.ValueAtReturn(out x) != null); 

+		Expect(1);

+		x = t; 

+	}

+

 	void GenericParameters(List<TypeParameter/*!*/>/*!*/ typeArgs) {

 		Contract.Requires(cce.NonNullElements(typeArgs));

 		IToken/*!*/ id; 

-		Expect(22);

+		Expect(23);

 		NoUSIdent(out id);

 		typeArgs.Add(new TypeParameter(id, id.val)); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			NoUSIdent(out id);

 			typeArgs.Add(new TypeParameter(id, id.val)); 

 		}

-		Expect(23);

+		Expect(24);

 	}

 

 	void FieldDecl(MemberModifiers mmod, List<MemberDecl/*!*/>/*!*/ mm) {

@@ -449,8 +455,8 @@ bool IsAttribute() {
 		Attributes attrs = null;

 		IToken/*!*/ id;  Type/*!*/ ty;

 		

-		while (!(la.kind == 0 || la.kind == 19)) {SynErr(116); Get();}

-		Expect(19);

+		while (!(la.kind == 0 || la.kind == 20)) {SynErr(117); Get();}

+		Expect(20);

 		if (mmod.IsStatic) { SemErr(t, "fields cannot be declared 'static'"); }

 		

 		while (la.kind == 6) {

@@ -458,13 +464,13 @@ bool IsAttribute() {
 		}

 		IdentType(out id, out ty);

 		mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			IdentType(out id, out ty);

 			mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); 

 		}

-		while (!(la.kind == 0 || la.kind == 18)) {SynErr(117); Get();}

-		Expect(18);

+		while (!(la.kind == 0 || la.kind == 12)) {SynErr(118); Get();}

+		Expect(12);

 	}

 

 	void FunctionDecl(MemberModifiers mmod, out Function/*!*/ f) {

@@ -488,7 +494,7 @@ bool IsAttribute() {
 		

 		if (la.kind == 44) {

 			Get();

-			if (la.kind == 24) {

+			if (la.kind == 25) {

 				Get();

 				isFunctionMethod = true; 

 			}

@@ -498,22 +504,22 @@ bool IsAttribute() {
 				Attribute(ref attrs);

 			}

 			NoUSIdent(out id);

-			if (la.kind == 22 || la.kind == 33) {

-				if (la.kind == 22) {

+			if (la.kind == 23 || la.kind == 34) {

+				if (la.kind == 23) {

 					GenericParameters(typeArgs);

 				}

 				Formals(true, isFunctionMethod, formals, out openParen);

 				Expect(5);

 				Type(out returnType);

-			} else if (la.kind == 27) {

+			} else if (la.kind == 28) {

 				Get();

 				signatureOmitted = true;

 				openParen = Token.NoToken; 

-			} else SynErr(118);

+			} else SynErr(119);

 		} else if (la.kind == 45) {

 			Get();

 			isPredicate = true; 

-			if (la.kind == 24) {

+			if (la.kind == 25) {

 				Get();

 				isFunctionMethod = true; 

 			}

@@ -524,22 +530,22 @@ bool IsAttribute() {
 			}

 			NoUSIdent(out id);

 			if (StartOf(3)) {

-				if (la.kind == 22) {

+				if (la.kind == 23) {

 					GenericParameters(typeArgs);

 				}

-				if (la.kind == 33) {

+				if (la.kind == 34) {

 					Formals(true, isFunctionMethod, formals, out openParen);

 					if (la.kind == 5) {

 						Get();

 						SemErr(t, "predicates do not have an explicitly declared return type; it is always bool"); 

 					}

 				}

-			} else if (la.kind == 27) {

+			} else if (la.kind == 28) {

 				Get();

 				signatureOmitted = true;

 				openParen = Token.NoToken; 

-			} else SynErr(119);

-		} else SynErr(120);

+			} else SynErr(120);

+		} else SynErr(121);

 		while (StartOf(4)) {

 			FunctionSpec(reqs, reads, ens, decreases);

 		}

@@ -578,10 +584,10 @@ bool IsAttribute() {
 		IToken bodyStart = Token.NoToken;

 		IToken bodyEnd = Token.NoToken;

 		

-		while (!(la.kind == 0 || la.kind == 24 || la.kind == 25)) {SynErr(121); Get();}

-		if (la.kind == 24) {

+		while (!(la.kind == 0 || la.kind == 25 || la.kind == 26)) {SynErr(122); Get();}

+		if (la.kind == 25) {

 			Get();

-		} else if (la.kind == 25) {

+		} else if (la.kind == 26) {

 			Get();

 			if (allowConstructor) {

 			 isConstructor = true;

@@ -589,7 +595,7 @@ bool IsAttribute() {
 			 SemErr(t, "constructors are only allowed in classes");

 			}

 			

-		} else SynErr(122);

+		} else SynErr(123);

 		if (isConstructor) {

 		 if (mmod.IsGhost) {

 		   SemErr(t, "constructors cannot be declared 'ghost'");

@@ -603,20 +609,20 @@ bool IsAttribute() {
 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

-		if (la.kind == 22 || la.kind == 33) {

-			if (la.kind == 22) {

+		if (la.kind == 23 || la.kind == 34) {

+			if (la.kind == 23) {

 				GenericParameters(typeArgs);

 			}

 			Formals(true, !mmod.IsGhost, ins, out openParen);

-			if (la.kind == 26) {

+			if (la.kind == 27) {

 				Get();

 				if (isConstructor) { SemErr(t, "constructors cannot have out-parameters"); } 

 				Formals(false, !mmod.IsGhost, outs, out openParen);

 			}

-		} else if (la.kind == 27) {

+		} else if (la.kind == 28) {

 			Get();

 			signatureOmitted = true; openParen = Token.NoToken; 

-		} else SynErr(123);

+		} else SynErr(124);

 		while (StartOf(5)) {

 			MethodSpec(req, mod, ens, dec, ref decAttrs, ref modAttrs);

 		}

@@ -645,7 +651,7 @@ bool IsAttribute() {
 			Attribute(ref attrs);

 		}

 		NoUSIdent(out id);

-		if (la.kind == 33) {

+		if (la.kind == 34) {

 			FormalsOptionalIds(formals);

 		}

 		ctors.Add(new DatatypeCtor(id, id.val, formals, attrs)); 

@@ -653,17 +659,17 @@ bool IsAttribute() {
 

 	void FormalsOptionalIds(List<Formal/*!*/>/*!*/ formals) {

 		Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id;  Type/*!*/ ty;  string/*!*/ name;  bool isGhost; 

-		Expect(33);

+		Expect(34);

 		if (StartOf(6)) {

 			TypeIdentOptional(out id, out name, out ty, out isGhost);

 			formals.Add(new Formal(id, name, ty, true, isGhost)); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				TypeIdentOptional(out id, out name, out ty, out isGhost);

 				formals.Add(new Formal(id, name, ty, true, isGhost)); 

 			}

 		}

-		Expect(34);

+		Expect(35);

 	}

 

 	void IdentType(out IToken/*!*/ id, out Type/*!*/ ty) {

@@ -747,22 +753,22 @@ bool IsAttribute() {
 		List<Type/*!*/>/*!*/ gt;

 		

 		switch (la.kind) {

-		case 35: {

+		case 36: {

 			Get();

 			tok = t; 

 			break;

 		}

-		case 36: {

+		case 37: {

 			Get();

 			tok = t;  ty = new NatType(); 

 			break;

 		}

-		case 37: {

+		case 38: {

 			Get();

 			tok = t;  ty = new IntType(); 

 			break;

 		}

-		case 38: {

+		case 39: {

 			Get();

 			tok = t;  gt = new List<Type/*!*/>(); 

 			GenericInstantiation(gt);

@@ -773,7 +779,7 @@ bool IsAttribute() {
 			

 			break;

 		}

-		case 39: {

+		case 40: {

 			Get();

 			tok = t;  gt = new List<Type/*!*/>(); 

 			GenericInstantiation(gt);

@@ -784,7 +790,7 @@ bool IsAttribute() {
 			

 			break;

 		}

-		case 40: {

+		case 41: {

 			Get();

 			tok = t;  gt = new List<Type/*!*/>(); 

 			GenericInstantiation(gt);

@@ -795,7 +801,7 @@ bool IsAttribute() {
 			

 			break;

 		}

-		case 41: {

+		case 42: {

 			Get();

 			tok = t;  gt = new List<Type/*!*/>(); 

 			GenericInstantiation(gt);

@@ -806,28 +812,28 @@ bool IsAttribute() {
 			

 			break;

 		}

-		case 1: case 3: case 42: {

+		case 1: case 3: case 43: {

 			ReferenceType(out tok, out ty);

 			break;

 		}

-		default: SynErr(124); break;

+		default: SynErr(125); break;

 		}

 	}

 

 	void Formals(bool incoming, bool allowGhostKeyword, List<Formal/*!*/>/*!*/ formals, out IToken openParen) {

 		Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id;  Type/*!*/ ty;  bool isGhost; 

-		Expect(33);

+		Expect(34);

 		openParen = t; 

 		if (la.kind == 1 || la.kind == 8) {

 			GIdentType(allowGhostKeyword, out id, out ty, out isGhost);

 			formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				GIdentType(allowGhostKeyword, out id, out ty, out isGhost);

 				formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); 

 			}

 		}

-		Expect(34);

+		Expect(35);

 	}

 

 	void MethodSpec(List<MaybeFreeExpression/*!*/>/*!*/ req, List<FrameExpression/*!*/>/*!*/ mod, List<MaybeFreeExpression/*!*/>/*!*/ ens,

@@ -835,8 +841,8 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Contract.Requires(cce.NonNullElements(req)); Contract.Requires(cce.NonNullElements(mod)); Contract.Requires(cce.NonNullElements(ens)); Contract.Requires(cce.NonNullElements(decreases));

 		Expression/*!*/ e;  FrameExpression/*!*/ fe;  bool isFree = false; Attributes ensAttrs = null;

 		

-		while (!(StartOf(7))) {SynErr(125); Get();}

-		if (la.kind == 28) {

+		while (!(StartOf(7))) {SynErr(126); Get();}

+		if (la.kind == 29) {

 			Get();

 			while (IsAttribute()) {

 				Attribute(ref modAttrs);

@@ -844,44 +850,44 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			if (StartOf(8)) {

 				FrameExpression(out fe);

 				mod.Add(fe); 

-				while (la.kind == 20) {

+				while (la.kind == 21) {

 					Get();

 					FrameExpression(out fe);

 					mod.Add(fe); 

 				}

 			}

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(126); Get();}

-			Expect(18);

-		} else if (la.kind == 29 || la.kind == 30 || la.kind == 31) {

-			if (la.kind == 29) {

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(127); Get();}

+			Expect(12);

+		} else if (la.kind == 30 || la.kind == 31 || la.kind == 32) {

+			if (la.kind == 30) {

 				Get();

 				isFree = true; 

 			}

-			if (la.kind == 30) {

+			if (la.kind == 31) {

 				Get();

 				Expression(out e);

-				while (!(la.kind == 0 || la.kind == 18)) {SynErr(127); Get();}

-				Expect(18);

+				while (!(la.kind == 0 || la.kind == 12)) {SynErr(128); Get();}

+				Expect(12);

 				req.Add(new MaybeFreeExpression(e, isFree)); 

-			} else if (la.kind == 31) {

+			} else if (la.kind == 32) {

 				Get();

 				while (IsAttribute()) {

 					Attribute(ref ensAttrs);

 				}

 				Expression(out e);

-				while (!(la.kind == 0 || la.kind == 18)) {SynErr(128); Get();}

-				Expect(18);

+				while (!(la.kind == 0 || la.kind == 12)) {SynErr(129); Get();}

+				Expect(12);

 				ens.Add(new MaybeFreeExpression(e, isFree, ensAttrs)); 

-			} else SynErr(129);

-		} else if (la.kind == 32) {

+			} else SynErr(130);

+		} else if (la.kind == 33) {

 			Get();

 			while (IsAttribute()) {

 				Attribute(ref decAttrs);

 			}

 			DecreasesList(decreases, false);

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(130); Get();}

-			Expect(18);

-		} else SynErr(131);

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(131); Get();}

+			Expect(12);

+		} else SynErr(132);

 	}

 

 	void BlockStmt(out BlockStmt/*!*/ block, out IToken bodyStart, out IToken bodyEnd) {

@@ -922,7 +928,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		 decreases.Add(e);

 		}

 		

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			PossiblyWildExpression(out e);

 			if (!allowWildcard && e is WildcardExpr) {

@@ -936,15 +942,15 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 

 	void GenericInstantiation(List<Type/*!*/>/*!*/ gt) {

 		Contract.Requires(cce.NonNullElements(gt)); Type/*!*/ ty; 

-		Expect(22);

+		Expect(23);

 		Type(out ty);

 		gt.Add(ty); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			Type(out ty);

 			gt.Add(ty); 

 		}

-		Expect(23);

+		Expect(24);

 	}

 

 	void ReferenceType(out IToken/*!*/ tok, out Type/*!*/ ty) {

@@ -953,7 +959,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		IToken moduleName = null;

 		List<Type/*!*/>/*!*/ gt;

 		

-		if (la.kind == 42) {

+		if (la.kind == 43) {

 			Get();

 			tok = t;  ty = new ObjectType(); 

 		} else if (la.kind == 3) {

@@ -972,53 +978,53 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (la.kind == 1) {

 			Ident(out tok);

 			gt = new List<Type/*!*/>(); 

-			if (la.kind == 43) {

+			if (la.kind == 14) {

 				moduleName = tok; 

 				Get();

 				Ident(out tok);

 			}

-			if (la.kind == 22) {

+			if (la.kind == 23) {

 				GenericInstantiation(gt);

 			}

 			ty = new UserDefinedType(tok, tok.val, gt, moduleName); 

-		} else SynErr(132);

+		} else SynErr(133);

 	}

 

 	void FunctionSpec(List<Expression/*!*/>/*!*/ reqs, List<FrameExpression/*!*/>/*!*/ reads, List<Expression/*!*/>/*!*/ ens, List<Expression/*!*/>/*!*/ decreases) {

 		Contract.Requires(cce.NonNullElements(reqs)); Contract.Requires(cce.NonNullElements(reads)); Contract.Requires(cce.NonNullElements(decreases));

 		Expression/*!*/ e;  FrameExpression/*!*/ fe; 

-		if (la.kind == 30) {

-			while (!(la.kind == 0 || la.kind == 30)) {SynErr(133); Get();}

+		if (la.kind == 31) {

+			while (!(la.kind == 0 || la.kind == 31)) {SynErr(134); Get();}

 			Get();

 			Expression(out e);

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(134); Get();}

-			Expect(18);

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(135); Get();}

+			Expect(12);

 			reqs.Add(e); 

 		} else if (la.kind == 46) {

 			Get();

 			if (StartOf(10)) {

 				PossiblyWildFrameExpression(out fe);

 				reads.Add(fe); 

-				while (la.kind == 20) {

+				while (la.kind == 21) {

 					Get();

 					PossiblyWildFrameExpression(out fe);

 					reads.Add(fe); 

 				}

 			}

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(135); Get();}

-			Expect(18);

-		} else if (la.kind == 31) {

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(136); Get();}

+			Expect(12);

+		} else if (la.kind == 32) {

 			Get();

 			Expression(out e);

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(136); Get();}

-			Expect(18);

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(137); Get();}

+			Expect(12);

 			ens.Add(e); 

-		} else if (la.kind == 32) {

+		} else if (la.kind == 33) {

 			Get();

 			DecreasesList(decreases, false);

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(137); Get();}

-			Expect(18);

-		} else SynErr(138);

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(138); Get();}

+			Expect(12);

+		} else SynErr(139);

 	}

 

 	void FunctionBody(out Expression/*!*/ e, out IToken bodyStart, out IToken bodyEnd) {

@@ -1037,7 +1043,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			fe = new FrameExpression(new WildcardExpr(t), null); 

 		} else if (StartOf(8)) {

 			FrameExpression(out fe);

-		} else SynErr(139);

+		} else SynErr(140);

 	}

 

 	void PossiblyWildExpression(out Expression/*!*/ e) {

@@ -1048,7 +1054,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			e = new WildcardExpr(t); 

 		} else if (StartOf(8)) {

 			Expression(out e);

-		} else SynErr(140);

+		} else SynErr(141);

 	}

 

 	void Stmt(List<Statement/*!*/>/*!*/ ss) {

@@ -1065,7 +1071,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		IToken bodyStart, bodyEnd;

 		int breakCount;

 		

-		while (!(StartOf(11))) {SynErr(141); Get();}

+		while (!(StartOf(11))) {SynErr(142); Get();}

 		switch (la.kind) {

 		case 6: {

 			BlockStmt(out bs, out bodyStart, out bodyEnd);

@@ -1084,11 +1090,11 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			PrintStmt(out s);

 			break;

 		}

-		case 1: case 2: case 17: case 33: case 92: case 93: case 94: case 95: case 96: case 97: case 98: {

+		case 1: case 2: case 19: case 34: case 92: case 93: case 94: case 95: case 96: case 97: case 98: {

 			UpdateStmt(out s);

 			break;

 		}

-		case 8: case 19: {

+		case 8: case 20: {

 			VarDeclStatement(out s);

 			break;

 		}

@@ -1123,14 +1129,14 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			if (la.kind == 1) {

 				NoUSIdent(out id);

 				label = id.val; 

-			} else if (la.kind == 18 || la.kind == 50) {

+			} else if (la.kind == 12 || la.kind == 50) {

 				while (la.kind == 50) {

 					Get();

 					breakCount++; 

 				}

-			} else SynErr(142);

-			while (!(la.kind == 0 || la.kind == 18)) {SynErr(143); Get();}

-			Expect(18);

+			} else SynErr(143);

+			while (!(la.kind == 0 || la.kind == 12)) {SynErr(144); Get();}

+			Expect(12);

 			s = label != null ? new BreakStmt(x, label) : new BreakStmt(x, breakCount); 

 			break;

 		}

@@ -1138,13 +1144,13 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			ReturnStmt(out s);

 			break;

 		}

-		case 27: {

+		case 28: {

 			Get();

 			s = new SkeletonStatement(t); 

-			Expect(18);

+			Expect(12);

 			break;

 		}

-		default: SynErr(144); break;

+		default: SynErr(145); break;

 		}

 	}

 

@@ -1159,10 +1165,10 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		}

 		if (StartOf(8)) {

 			Expression(out e);

-		} else if (la.kind == 27) {

+		} else if (la.kind == 28) {

 			Get();

-		} else SynErr(145);

-		Expect(18);

+		} else SynErr(146);

+		Expect(12);

 		if (e == null) {

 		 s = new SkeletonStatement(new AssertStmt(x, new LiteralExpr(x, true), attrs), true, false);

 		} else {

@@ -1176,7 +1182,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Expect(54);

 		x = t; 

 		Expression(out e);

-		Expect(18);

+		Expect(12);

 		s = new AssumeStmt(x, e); 

 	}

 

@@ -1188,12 +1194,12 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		x = t; 

 		AttributeArg(out arg);

 		args.Add(arg); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			AttributeArg(out arg);

 			args.Add(arg); 

 		}

-		Expect(18);

+		Expect(12);

 		s = new PrintStmt(x, args); 

 	}

 

@@ -1209,15 +1215,15 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		Lhs(out e);

 		x = e.tok; 

-		if (la.kind == 6 || la.kind == 18) {

+		if (la.kind == 6 || la.kind == 12) {

 			while (la.kind == 6) {

 				Attribute(ref attrs);

 			}

-			Expect(18);

+			Expect(12);

 			rhss.Add(new ExprRhs(e, attrs)); 

-		} else if (la.kind == 20 || la.kind == 52 || la.kind == 53) {

+		} else if (la.kind == 21 || la.kind == 52 || la.kind == 53) {

 			lhss.Add(e);  lhs0 = e; 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				Lhs(out e);

 				lhss.Add(e); 

@@ -1227,7 +1233,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 				x = t; 

 				Rhs(out r, lhs0);

 				rhss.Add(r); 

-				while (la.kind == 20) {

+				while (la.kind == 21) {

 					Get();

 					Rhs(out r, lhs0);

 					rhss.Add(r); 

@@ -1240,12 +1246,12 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 					suchThatAssume = t; 

 				}

 				Expression(out suchThat);

-			} else SynErr(146);

-			Expect(18);

+			} else SynErr(147);

+			Expect(12);

 		} else if (la.kind == 5) {

 			Get();

 			SemErr(t, "invalid statement (did you forget the 'label' keyword?)"); 

-		} else SynErr(147);

+		} else SynErr(148);

 		if (suchThat != null) {

 		 s = new AssignSuchThatStmt(x, lhss, suchThat, suchThatAssume);

 		} else {

@@ -1267,11 +1273,11 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 			isGhost = true;  x = t; 

 		}

-		Expect(19);

+		Expect(20);

 		if (!isGhost) { x = t; } 

 		LocalIdentTypeOptional(out d, isGhost);

 		lhss.Add(d); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			LocalIdentTypeOptional(out d, isGhost);

 			lhss.Add(d); 

@@ -1285,7 +1291,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 				

 				Rhs(out r, lhs0);

 				rhss.Add(r); 

-				while (la.kind == 20) {

+				while (la.kind == 21) {

 					Get();

 					Rhs(out r, lhs0);

 					rhss.Add(r); 

@@ -1300,7 +1306,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 				Expression(out suchThat);

 			}

 		}

-		Expect(18);

+		Expect(12);

 		ConcreteUpdateStatement update;

 		if (suchThat != null) {

 		 var ies = new List<Expression>();

@@ -1334,8 +1340,8 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		Expect(59);

 		x = t; 

-		if (la.kind == 27 || la.kind == 33) {

-			if (la.kind == 33) {

+		if (la.kind == 28 || la.kind == 34) {

+			if (la.kind == 34) {

 				Guard(out guard);

 			} else {

 				Get();

@@ -1350,7 +1356,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 				} else if (la.kind == 6) {

 					BlockStmt(out bs, out bodyStart, out bodyEnd);

 					els = bs; 

-				} else SynErr(148);

+				} else SynErr(149);

 			}

 			if (guardOmitted) {

 			 ifStmt = new SkeletonStatement(new IfStmt(x, guard, thn, els), true, false);

@@ -1361,7 +1367,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (la.kind == 6) {

 			AlternativeBlock(out alternatives);

 			ifStmt = new AlternativeStmt(x, alternatives); 

-		} else SynErr(149);

+		} else SynErr(150);

 	}

 

 	void WhileStmt(out Statement/*!*/ stmt) {

@@ -1379,8 +1385,8 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		Expect(63);

 		x = t; 

-		if (la.kind == 27 || la.kind == 33) {

-			if (la.kind == 33) {

+		if (la.kind == 28 || la.kind == 34) {

+			if (la.kind == 34) {

 				Guard(out guard);

 				Contract.Assume(guard == null || cce.Owner.None(guard)); 

 			} else {

@@ -1390,10 +1396,10 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			LoopSpec(out invariants, out decreases, out mod, ref decAttrs, ref modAttrs);

 			if (la.kind == 6) {

 				BlockStmt(out body, out bodyStart, out bodyEnd);

-			} else if (la.kind == 27) {

+			} else if (la.kind == 28) {

 				Get();

 				bodyOmitted = true; 

-			} else SynErr(150);

+			} else SynErr(151);

 			if (guardOmitted || bodyOmitted) {

 			 if (decreases.Count != 0) {

 			   SemErr(decreases[0].tok, "'decreases' clauses are not allowed on refining loops");

@@ -1414,7 +1420,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			LoopSpec(out invariants, out decreases, out mod, ref decAttrs, ref modAttrs);

 			AlternativeBlock(out alternatives);

 			stmt = new AlternativeLoopStmt(x, invariants, new Specification<Expression>(decreases, decAttrs), new Specification<FrameExpression>(mod, modAttrs), alternatives); 

-		} else SynErr(151);

+		} else SynErr(152);

 	}

 

 	void MatchStmt(out Statement/*!*/ s) {

@@ -1447,7 +1453,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		Expect(68);

 		x = t; 

-		Expect(33);

+		Expect(34);

 		if (la.kind == 1) {

 			List<BoundVar/*!*/> bvarsX;  Attributes attrsX;  Expression rangeX; 

 			QuantifierDomain(out bvarsX, out attrsX, out rangeX);

@@ -1457,16 +1463,16 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		if (bvars == null) { bvars = new List<BoundVar>(); }

 		if (range == null) { range = new LiteralExpr(x, true); }

 		

-		Expect(34);

-		while (la.kind == 29 || la.kind == 31) {

+		Expect(35);

+		while (la.kind == 30 || la.kind == 32) {

 			isFree = false; 

-			if (la.kind == 29) {

+			if (la.kind == 30) {

 				Get();

 				isFree = true; 

 			}

-			Expect(31);

+			Expect(32);

 			Expression(out e);

-			Expect(18);

+			Expect(12);

 			ens.Add(new MaybeFreeExpression(e, isFree)); 

 		}

 		BlockStmt(out block, out bodyStart, out bodyEnd);

@@ -1483,13 +1489,13 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		if (StartOf(13)) {

 			Rhs(out r, null);

 			rhss = new List<AssignmentRhs>(); rhss.Add(r); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				Rhs(out r, null);

 				rhss.Add(r); 

 			}

 		}

-		Expect(18);

+		Expect(12);

 		s = new ReturnStmt(returnTok, rhss); 

 	}

 

@@ -1506,7 +1512,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 			newToken = t; 

 			TypeAndToken(out x, out ty);

-			if (la.kind == 33 || la.kind == 43 || la.kind == 56) {

+			if (la.kind == 14 || la.kind == 34 || la.kind == 56) {

 				if (la.kind == 56) {

 					Get();

 					ee = new List<Expression>(); 

@@ -1514,15 +1520,15 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 					Expect(57);

 					UserDefinedType tmp = theBuiltIns.ArrayType(x, ee.Count, new IntType(), true);

 					

-				} else if (la.kind == 43) {

+				} else if (la.kind == 14) {

 					Get();

 					Ident(out x);

-					Expect(33);

+					Expect(34);

 					args = new List<Expression/*!*/>(); 

 					if (StartOf(8)) {

 						Expressions(args);

 					}

-					Expect(34);

+					Expect(35);

 					initCall = new CallStmt(x, new List<Expression>(), receiverForInitCall, x.val, args); 

 				} else {

 					Get();

@@ -1540,7 +1546,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 					if (StartOf(8)) {

 						Expressions(args);

 					}

-					Expect(34);

+					Expect(35);

 					if (x != null) {

 					 initCall = new CallStmt(x, new List<Expression>(), receiverForInitCall, x.val, args);

 					}

@@ -1564,7 +1570,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (StartOf(8)) {

 			Expression(out e);

 			r = new ExprRhs(e); 

-		} else SynErr(152);

+		} else SynErr(153);

 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

@@ -1576,23 +1582,23 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		if (la.kind == 1) {

 			DottedIdentifiersAndFunction(out e);

-			while (la.kind == 43 || la.kind == 56) {

+			while (la.kind == 14 || la.kind == 56) {

 				Suffix(ref e);

 			}

 		} else if (StartOf(14)) {

 			ConstAtomExpression(out e);

 			Suffix(ref e);

-			while (la.kind == 43 || la.kind == 56) {

+			while (la.kind == 14 || la.kind == 56) {

 				Suffix(ref e);

 			}

-		} else SynErr(153);

+		} else SynErr(154);

 	}

 

 	void Expressions(List<Expression/*!*/>/*!*/ args) {

 		Contract.Requires(cce.NonNullElements(args)); Expression/*!*/ e; 

 		Expression(out e);

 		args.Add(e); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			Expression(out e);

 			args.Add(e); 

@@ -1601,15 +1607,15 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 

 	void Guard(out Expression e) {

 		Expression/*!*/ ee;  e = null; 

-		Expect(33);

+		Expect(34);

 		if (la.kind == 47) {

 			Get();

 			e = null; 

 		} else if (StartOf(8)) {

 			Expression(out ee);

 			e = ee; 

-		} else SynErr(154);

-		Expect(34);

+		} else SynErr(155);

+		Expect(35);

 	}

 

 	void AlternativeBlock(out List<GuardedAlternative> alternatives) {

@@ -1641,22 +1647,22 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		mod = null;

 		

 		while (StartOf(15)) {

-			if (la.kind == 29 || la.kind == 64) {

+			if (la.kind == 30 || la.kind == 64) {

 				Invariant(out invariant);

-				while (!(la.kind == 0 || la.kind == 18)) {SynErr(155); Get();}

-				Expect(18);

+				while (!(la.kind == 0 || la.kind == 12)) {SynErr(156); Get();}

+				Expect(12);

 				invariants.Add(invariant); 

-			} else if (la.kind == 32) {

-				while (!(la.kind == 0 || la.kind == 32)) {SynErr(156); Get();}

+			} else if (la.kind == 33) {

+				while (!(la.kind == 0 || la.kind == 33)) {SynErr(157); Get();}

 				Get();

 				while (IsAttribute()) {

 					Attribute(ref decAttrs);

 				}

 				DecreasesList(decreases, true);

-				while (!(la.kind == 0 || la.kind == 18)) {SynErr(157); Get();}

-				Expect(18);

+				while (!(la.kind == 0 || la.kind == 12)) {SynErr(158); Get();}

+				Expect(12);

 			} else {

-				while (!(la.kind == 0 || la.kind == 28)) {SynErr(158); Get();}

+				while (!(la.kind == 0 || la.kind == 29)) {SynErr(159); Get();}

 				Get();

 				while (IsAttribute()) {

 					Attribute(ref modAttrs);

@@ -1665,22 +1671,22 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 				if (StartOf(8)) {

 					FrameExpression(out fe);

 					mod.Add(fe); 

-					while (la.kind == 20) {

+					while (la.kind == 21) {

 						Get();

 						FrameExpression(out fe);

 						mod.Add(fe); 

 					}

 				}

-				while (!(la.kind == 0 || la.kind == 18)) {SynErr(159); Get();}

-				Expect(18);

+				while (!(la.kind == 0 || la.kind == 12)) {SynErr(160); Get();}

+				Expect(12);

 			}

 		}

 	}

 

 	void Invariant(out MaybeFreeExpression/*!*/ invariant) {

 		bool isFree = false; Expression/*!*/ e; List<string> ids = new List<string>(); invariant = null; Attributes attrs = null; 

-		while (!(la.kind == 0 || la.kind == 29 || la.kind == 64)) {SynErr(160); Get();}

-		if (la.kind == 29) {

+		while (!(la.kind == 0 || la.kind == 30 || la.kind == 64)) {SynErr(161); Get();}

+		if (la.kind == 30) {

 			Get();

 			isFree = true; 

 		}

@@ -1702,16 +1708,16 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Expect(61);

 		x = t; 

 		Ident(out id);

-		if (la.kind == 33) {

+		if (la.kind == 34) {

 			Get();

 			IdentTypeOptional(out bv);

 			arguments.Add(bv); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				IdentTypeOptional(out bv);

 				arguments.Add(bv); 

 			}

-			Expect(34);

+			Expect(35);

 		}

 		Expect(62);

 		while (StartOf(9)) {

@@ -1728,7 +1734,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (StartOf(8)) {

 			Expression(out e);

 			arg = new Attributes.Argument(t, e); 

-		} else SynErr(161);

+		} else SynErr(162);

 	}

 

 	void QuantifierDomain(out List<BoundVar/*!*/> bvars, out Attributes attrs, out Expression range) {

@@ -1739,7 +1745,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		IdentTypeOptional(out bv);

 		bvars.Add(bv); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			IdentTypeOptional(out bv);

 			bvars.Add(bv); 

@@ -1747,7 +1753,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		while (la.kind == 6) {

 			Attribute(ref attrs);

 		}

-		if (la.kind == 17) {

+		if (la.kind == 19) {

 			Get();

 			Expression(out range);

 		}

@@ -1780,7 +1786,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 70) {

 			Get();

-		} else SynErr(162);

+		} else SynErr(163);

 	}

 

 	void LogicalExpression(out Expression/*!*/ e0) {

@@ -1818,7 +1824,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 72) {

 			Get();

-		} else SynErr(163);

+		} else SynErr(164);

 	}

 

 	void RelationalExpression(out Expression/*!*/ e) {

@@ -1916,7 +1922,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 74) {

 			Get();

-		} else SynErr(164);

+		} else SynErr(165);

 	}

 

 	void OrOp() {

@@ -1924,7 +1930,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 76) {

 			Get();

-		} else SynErr(165);

+		} else SynErr(166);

 	}

 

 	void Term(out Expression/*!*/ e0) {

@@ -1948,12 +1954,12 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			x = t;  op = BinaryExpr.Opcode.Eq; 

 			break;

 		}

-		case 22: {

+		case 23: {

 			Get();

 			x = t;  op = BinaryExpr.Opcode.Lt; 

 			break;

 		}

-		case 23: {

+		case 24: {

 			Get();

 			x = t;  op = BinaryExpr.Opcode.Gt; 

 			break;

@@ -2016,7 +2022,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			x = t;  op = BinaryExpr.Opcode.Ge; 

 			break;

 		}

-		default: SynErr(166); break;

+		default: SynErr(167); break;

 		}

 	}

 

@@ -2038,7 +2044,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (la.kind == 88) {

 			Get();

 			x = t;  op = BinaryExpr.Opcode.Sub; 

-		} else SynErr(167);

+		} else SynErr(168);

 	}

 

 	void UnaryExpression(out Expression/*!*/ e) {

@@ -2058,13 +2064,13 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			e = new UnaryExpr(x, UnaryExpr.Opcode.Not, e); 

 			break;

 		}

-		case 19: case 38: case 54: case 59: case 65: case 66: case 101: case 102: case 103: case 104: {

+		case 20: case 39: case 54: case 59: case 65: case 66: case 101: case 102: case 103: case 104: {

 			EndlessExpression(out e);

 			break;

 		}

 		case 1: {

 			DottedIdentifiersAndFunction(out e);

-			while (la.kind == 43 || la.kind == 56) {

+			while (la.kind == 14 || la.kind == 56) {

 				Suffix(ref e);

 			}

 			break;

@@ -2073,22 +2079,22 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			DisplayExpr(out e);

 			break;

 		}

-		case 39: {

+		case 40: {

 			MultiSetExpr(out e);

 			break;

 		}

-		case 41: {

+		case 42: {

 			MapExpr(out e);

 			break;

 		}

-		case 2: case 17: case 33: case 92: case 93: case 94: case 95: case 96: case 97: case 98: {

+		case 2: case 19: case 34: case 92: case 93: case 94: case 95: case 96: case 97: case 98: {

 			ConstAtomExpression(out e);

-			while (la.kind == 43 || la.kind == 56) {

+			while (la.kind == 14 || la.kind == 56) {

 				Suffix(ref e);

 			}

 			break;

 		}

-		default: SynErr(168); break;

+		default: SynErr(169); break;

 		}

 	}

 

@@ -2103,7 +2109,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (la.kind == 90) {

 			Get();

 			x = t;  op = BinaryExpr.Opcode.Mod; 

-		} else SynErr(169);

+		} else SynErr(170);

 	}

 

 	void NegOp() {

@@ -2111,7 +2117,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 91) {

 			Get();

-		} else SynErr(170);

+		} else SynErr(171);

 	}

 

 	void EndlessExpression(out Expression e) {

@@ -2141,7 +2147,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			QuantifierGuts(out e);

 			break;

 		}

-		case 38: {

+		case 39: {

 			ComprehensionExpr(out e);

 			break;

 		}

@@ -2149,7 +2155,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 			x = t; 

 			Expression(out e0);

-			Expect(18);

+			Expect(12);

 			Expression(out e1);

 			e = new AssertExpr(x, e0, e1); 

 			break;

@@ -2158,19 +2164,19 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 			x = t; 

 			Expression(out e0);

-			Expect(18);

+			Expect(12);

 			Expression(out e1);

 			e = new AssumeExpr(x, e0, e1); 

 			break;

 		}

-		case 19: {

+		case 20: {

 			Get();

 			x = t;

 			letVars = new List<BoundVar>();

 			letRHSs = new List<Expression>(); 

 			IdentTypeOptional(out d);

 			letVars.Add(d); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				IdentTypeOptional(out d);

 				letVars.Add(d); 

@@ -2178,17 +2184,17 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Expect(52);

 			Expression(out e);

 			letRHSs.Add(e); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				Expression(out e);

 				letRHSs.Add(e); 

 			}

-			Expect(18);

+			Expect(12);

 			Expression(out e);

 			e = new LetExpr(x, letVars, letRHSs, e); 

 			break;

 		}

-		default: SynErr(171); break;

+		default: SynErr(172); break;

 		}

 	}

 

@@ -2199,18 +2205,18 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		

 		Ident(out id);

 		idents.Add(id); 

-		while (la.kind == 43) {

+		while (la.kind == 14) {

 			Get();

 			Ident(out id);

 			idents.Add(id); 

 		}

-		if (la.kind == 33) {

+		if (la.kind == 34) {

 			Get();

 			openParen = t;  args = new List<Expression>(); 

 			if (StartOf(8)) {

 				Expressions(args);

 			}

-			Expect(34);

+			Expect(35);

 		}

 		e = new IdentifierSequence(idents, openParen, args); 

 	}

@@ -2221,16 +2227,16 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		List<Expression> multipleIndices = null;

 		bool func = false;

 		

-		if (la.kind == 43) {

+		if (la.kind == 14) {

 			Get();

 			Ident(out id);

-			if (la.kind == 33) {

+			if (la.kind == 34) {

 				Get();

 				IToken openParen = t;  args = new List<Expression/*!*/>();  func = true; 

 				if (StartOf(8)) {

 					Expressions(args);

 				}

-				Expect(34);

+				Expect(35);

 				e = new FunctionCallExpr(id, id.val, e, openParen, args); 

 			}

 			if (!func) { e = new ExprDotName(id, e, id.val); } 

@@ -2251,8 +2257,8 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 					Get();

 					Expression(out ee);

 					e1 = ee; 

-				} else if (la.kind == 20 || la.kind == 57) {

-					while (la.kind == 20) {

+				} else if (la.kind == 21 || la.kind == 57) {

+					while (la.kind == 21) {

 						Get();

 						Expression(out ee);

 						if (multipleIndices == null) {

@@ -2262,7 +2268,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 						multipleIndices.Add(ee);

 						

 					}

-				} else SynErr(172);

+				} else SynErr(173);

 			} else if (la.kind == 100) {

 				Get();

 				anyDots = true; 

@@ -2270,7 +2276,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 					Expression(out ee);

 					e1 = ee; 

 				}

-			} else SynErr(173);

+			} else SynErr(174);

 			if (multipleIndices != null) {

 			 e = new MultiSelectExpr(x, e, multipleIndices);

 			 // make sure an array class with this dimensionality exists

@@ -2294,7 +2300,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			}

 			

 			Expect(57);

-		} else SynErr(174);

+		} else SynErr(175);

 	}

 

 	void DisplayExpr(out Expression e) {

@@ -2318,7 +2324,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			}

 			e = new SeqDisplayExpr(x, elements); 

 			Expect(57);

-		} else SynErr(175);

+		} else SynErr(176);

 	}

 

 	void MultiSetExpr(out Expression e) {

@@ -2326,7 +2332,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		IToken/*!*/ x = null;  List<Expression/*!*/>/*!*/ elements;

 		e = dummyExpr;

 		

-		Expect(39);

+		Expect(40);

 		x = t; 

 		if (la.kind == 6) {

 			Get();

@@ -2336,15 +2342,15 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			}

 			e = new MultiSetDisplayExpr(x, elements);

 			Expect(7);

-		} else if (la.kind == 33) {

+		} else if (la.kind == 34) {

 			Get();

 			x = t;  elements = new List<Expression/*!*/>(); 

 			Expression(out e);

 			e = new MultiSetFormingExpr(x, e); 

-			Expect(34);

+			Expect(35);

 		} else if (StartOf(18)) {

 			SemErr("multiset must be followed by multiset literal or expression to coerce in parentheses."); 

-		} else SynErr(176);

+		} else SynErr(177);

 	}

 

 	void MapExpr(out Expression e) {

@@ -2353,7 +2359,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		List<ExpressionPair/*!*/>/*!*/ elements;

 		e = dummyExpr;

 		

-		Expect(41);

+		Expect(42);

 		x = t; 

 		if (la.kind == 56) {

 			Get();

@@ -2371,14 +2377,14 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			

 			IdentTypeOptional(out bv);

 			bvars.Add(bv); 

-			Expect(17);

+			Expect(19);

 			Expression(out range);

 			QSep();

 			Expression(out body);

 			e = new MapComprehension(x, bvars, range, body); 

 		} else if (StartOf(18)) {

 			SemErr("map must be followed by literal in brackets or comprehension."); 

-		} else SynErr(177);

+		} else SynErr(178);

 	}

 

 	void ConstAtomExpression(out Expression/*!*/ e) {

@@ -2415,47 +2421,47 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		case 96: {

 			Get();

 			x = t; 

-			Expect(33);

-			Expression(out e);

 			Expect(34);

+			Expression(out e);

+			Expect(35);

 			e = new FreshExpr(x, e); 

 			break;

 		}

 		case 97: {

 			Get();

 			x = t; 

-			Expect(33);

-			Expression(out e);

 			Expect(34);

+			Expression(out e);

+			Expect(35);

 			e = new AllocatedExpr(x, e); 

 			break;

 		}

 		case 98: {

 			Get();

 			x = t; 

-			Expect(33);

-			Expression(out e);

 			Expect(34);

+			Expression(out e);

+			Expect(35);

 			e = new OldExpr(x, e); 

 			break;

 		}

-		case 17: {

+		case 19: {

 			Get();

 			x = t; 

 			Expression(out e);

 			e = new UnaryExpr(x, UnaryExpr.Opcode.SeqLength, e); 

-			Expect(17);

+			Expect(19);

 			break;

 		}

-		case 33: {

+		case 34: {

 			Get();

 			x = t; 

 			Expression(out e);

 			e = new ParensExpression(x, e); 

-			Expect(34);

+			Expect(35);

 			break;

 		}

-		default: SynErr(178); break;

+		default: SynErr(179); break;

 		}

 	}

 

@@ -2477,7 +2483,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Expect(52);

 		Expression(out r);

 		elements.Add(new ExpressionPair(d,r)); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			Expression(out d);

 			Expect(52);

@@ -2491,7 +2497,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 106) {

 			Get();

-		} else SynErr(179);

+		} else SynErr(180);

 	}

 

 	void MatchExpression(out Expression/*!*/ e) {

@@ -2522,7 +2528,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		} else if (la.kind == 103 || la.kind == 104) {

 			Exists();

 			x = t; 

-		} else SynErr(180);

+		} else SynErr(181);

 		QuantifierDomain(out bvars, out attrs, out range);

 		QSep();

 		Expression(out body);

@@ -2542,16 +2548,16 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Expression/*!*/ range;

 		Expression body = null;

 		

-		Expect(38);

+		Expect(39);

 		x = t; 

 		IdentTypeOptional(out bv);

 		bvars.Add(bv); 

-		while (la.kind == 20) {

+		while (la.kind == 21) {

 			Get();

 			IdentTypeOptional(out bv);

 			bvars.Add(bv); 

 		}

-		Expect(17);

+		Expect(19);

 		Expression(out range);

 		if (la.kind == 105 || la.kind == 106) {

 			QSep();

@@ -2571,16 +2577,16 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		Expect(61);

 		x = t; 

 		Ident(out id);

-		if (la.kind == 33) {

+		if (la.kind == 34) {

 			Get();

 			IdentTypeOptional(out bv);

 			arguments.Add(bv); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				IdentTypeOptional(out bv);

 				arguments.Add(bv); 

 			}

-			Expect(34);

+			Expect(35);

 		}

 		Expect(62);

 		Expression(out body);

@@ -2592,7 +2598,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 102) {

 			Get();

-		} else SynErr(181);

+		} else SynErr(182);

 	}

 

 	void Exists() {

@@ -2600,7 +2606,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Get();

 		} else if (la.kind == 104) {

 			Get();

-		} else SynErr(182);

+		} else SynErr(183);

 	}

 

 	void AttributeBody(ref Attributes attrs) {

@@ -2614,7 +2620,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 		if (StartOf(19)) {

 			AttributeArg(out aArg);

 			aArgs.Add(aArg); 

-			while (la.kind == 20) {

+			while (la.kind == 21) {

 				Get();

 				AttributeArg(out aArg);

 				aArgs.Add(aArg); 

@@ -2636,26 +2642,26 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 	}

 

 	static readonly bool[,]/*!*/ set = {

-		{T,T,T,x, x,x,T,x, T,x,x,x, T,x,T,T, x,T,T,T, x,x,x,x, T,T,x,T, T,T,T,T, T,T,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,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, 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, T,T,x,x, T,T,T,T, x,x,x,T, x,T,x,x, T,T,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, T,x,x,x, x,T,x,x, 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, 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,T,T, T,T,x,x, T,T,T,T, x,x,x,T, x,T,T,x, T,T,x,x, x,x,T,T, T,T,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,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x},

-		{x,x,x,x, x,x,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,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, 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,T,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,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,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,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, 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,T,T,x, x,x,T,x, x,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,x, x,x,x,x, x,T,x,x, x,x,T,T, x,T,x,x, x,x,x,x, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

-		{x,T,T,x, x,x,T,x, T,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,T, x,x,x,x, x,T,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,T, 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, T,T,T,T, T,T,T,x, x,x,x,x, x,x,x,x, x},

-		{x,T,T,x, x,x,T,x, x,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,x, x,x,x,x, x,T,x,x, x,x,T,T, x,T,x,x, x,x,x,T, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

-		{T,T,T,x, x,x,T,x, T,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,T, x,x,x,x, x,T,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,T, 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, T,T,T,T, T,T,T,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,x,x,x, x,x,x,x, 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,x,x,x, x},

-		{x,T,T,x, x,x,T,x, x,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,x, x,x,x,x, x,T,x,x, x,x,T,T, x,T,x,x, x,x,x,T, x,x,x,x, x,x,T,T, T,x,T,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

-		{x,x,T,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,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, 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, 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, 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},

+		{T,T,T,x, x,x,T,x, T,x,x,x, T,x,x,T, x,T,T,T, T,x,x,x, x,T,T,x, T,T,T,T, T,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,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, 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, T,T,x,x, x,x,x,T, T,T,T,x, T,x,T,x, x,T,T,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, T,x,x,x, x,x,x,x, 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, 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,T,T, T,T,x,x, x,x,x,T, T,T,T,x, T,x,T,T, x,T,T,x, x,x,x,T, T,T,T,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,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x},

+		{x,x,x,x, x,x,x,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,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,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,T,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, 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,x,x, x,x,x,x, x,x,x,x, x,x,x,x, x,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,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,T,T,x, x,x,T,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, T,x,T,x, x,x,x,x, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

+		{x,T,T,x, x,x,T,x, T,x,x,x, x,x,x,x, x,x,x,T, T,x,x,x, x,x,x,x, T,x,x,x, x,x,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,T, 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, T,T,T,T, T,T,T,x, x,x,x,x, x,x,x,x, x},

+		{x,T,T,x, x,x,T,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, T,x,T,x, x,x,x,T, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

+		{T,T,T,x, x,x,T,x, T,x,x,x, x,x,x,x, x,x,x,T, T,x,x,x, x,x,x,x, T,x,x,x, x,x,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,T,T,T, x,x,T,x, x,x,x,T, x,x,x,T, 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, T,T,T,T, T,T,T,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,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, 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,T,T,x, x,x,T,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, T,x,T,x, x,x,x,T, x,x,x,x, x,x,T,T, T,x,T,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x},

+		{x,x,T,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,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, 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,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, 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,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,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,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, x,x,T,T, x,x,x,x, x,x,x,x, x,T,T,x, T,x,T,T, 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, T,x,x,x, x,T,x,x, T,T,T,x, x,x,x,x, x,T,T,T, T,T,T,T, T,T,T,T, T,T,T,T, T,T,T,T, T,T,T,x, x,x,x,x, x,x,x,T, T,x,x,x, x,T,T,x, x},

-		{x,T,T,x, T,x,T,x, x,x,x,x, x,x,x,x, x,T,x,T, x,x,x,x, x,x,x,x, x,x,x,x, x,T,x,x, x,x,T,T, x,T,x,x, x,x,x,x, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,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,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,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, x,x,T,T, x,x,x,x, T,x,x,x, x,x,x,T, x,T,x,T, T,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, x,x,x,x, x,x,x,T, T,x,x,x, T,x,x,x, x,T,x,x, T,T,T,x, x,x,x,x, x,T,T,T, T,T,T,T, T,T,T,T, T,T,T,T, T,T,T,T, T,T,T,x, x,x,x,x, x,x,x,T, T,x,x,x, x,T,T,x, x},

+		{x,T,T,x, T,x,T,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, T,x,T,x, x,x,x,x, x,x,x,x, x,x,T,x, T,x,x,T, x,x,x,x, x,T,T,x, x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,T, x,x,x,x, T,x,x,T, T,T,T,T, T,T,T,x, x,T,T,T, T,x,x,x, x}

 

 	};

 } // end Parser

@@ -2691,39 +2697,39 @@ public class Errors {
 			case 8: s = "\"ghost\" expected"; break;

 			case 9: s = "\"module\" expected"; break;

 			case 10: s = "\"refines\" expected"; break;

-			case 11: s = "\"imports\" expected"; break;

-			case 12: s = "\"class\" expected"; break;

-			case 13: s = "\"static\" expected"; break;

-			case 14: s = "\"datatype\" expected"; break;

-			case 15: s = "\"codatatype\" expected"; break;

-			case 16: s = "\"=\" expected"; break;

-			case 17: s = "\"|\" expected"; break;

-			case 18: s = "\";\" expected"; break;

-			case 19: s = "\"var\" expected"; break;

-			case 20: s = "\",\" expected"; break;

-			case 21: s = "\"type\" expected"; break;

-			case 22: s = "\"<\" expected"; break;

-			case 23: s = "\">\" expected"; break;

-			case 24: s = "\"method\" expected"; break;

-			case 25: s = "\"constructor\" expected"; break;

-			case 26: s = "\"returns\" expected"; break;

-			case 27: s = "\"...\" expected"; break;

-			case 28: s = "\"modifies\" expected"; break;

-			case 29: s = "\"free\" expected"; break;

-			case 30: s = "\"requires\" expected"; break;

-			case 31: s = "\"ensures\" expected"; break;

-			case 32: s = "\"decreases\" expected"; break;

-			case 33: s = "\"(\" expected"; break;

-			case 34: s = "\")\" expected"; break;

-			case 35: s = "\"bool\" expected"; break;

-			case 36: s = "\"nat\" expected"; break;

-			case 37: s = "\"int\" expected"; break;

-			case 38: s = "\"set\" expected"; break;

-			case 39: s = "\"multiset\" expected"; break;

-			case 40: s = "\"seq\" expected"; break;

-			case 41: s = "\"map\" expected"; break;

-			case 42: s = "\"object\" expected"; break;

-			case 43: s = "\".\" expected"; break;

+			case 11: s = "\"=\" expected"; break;

+			case 12: s = "\";\" expected"; break;

+			case 13: s = "\"as\" expected"; break;

+			case 14: s = "\".\" expected"; break;

+			case 15: s = "\"class\" expected"; break;

+			case 16: s = "\"static\" expected"; break;

+			case 17: s = "\"datatype\" expected"; break;

+			case 18: s = "\"codatatype\" expected"; break;

+			case 19: s = "\"|\" expected"; break;

+			case 20: s = "\"var\" expected"; break;

+			case 21: s = "\",\" expected"; break;

+			case 22: s = "\"type\" expected"; break;

+			case 23: s = "\"<\" expected"; break;

+			case 24: s = "\">\" expected"; break;

+			case 25: s = "\"method\" expected"; break;

+			case 26: s = "\"constructor\" expected"; break;

+			case 27: s = "\"returns\" expected"; break;

+			case 28: s = "\"...\" expected"; break;

+			case 29: s = "\"modifies\" expected"; break;

+			case 30: s = "\"free\" expected"; break;

+			case 31: s = "\"requires\" expected"; break;

+			case 32: s = "\"ensures\" expected"; break;

+			case 33: s = "\"decreases\" expected"; break;

+			case 34: s = "\"(\" expected"; break;

+			case 35: s = "\")\" expected"; break;

+			case 36: s = "\"bool\" expected"; break;

+			case 37: s = "\"nat\" expected"; break;

+			case 38: s = "\"int\" expected"; break;

+			case 39: s = "\"set\" expected"; break;

+			case 40: s = "\"multiset\" expected"; break;

+			case 41: s = "\"seq\" expected"; break;

+			case 42: s = "\"map\" expected"; break;

+			case 43: s = "\"object\" expected"; break;

 			case 44: s = "\"function\" expected"; break;

 			case 45: s = "\"predicate\" expected"; break;

 			case 46: s = "\"reads\" expected"; break;

@@ -2790,79 +2796,80 @@ public class Errors {
 			case 107: s = "??? expected"; break;

 			case 108: s = "invalid Dafny"; break;

 			case 109: s = "invalid SubModuleDecl"; break;

-			case 110: s = "this symbol not expected in ClassDecl"; break;

-			case 111: s = "this symbol not expected in DatatypeDecl"; break;

-			case 112: s = "invalid DatatypeDecl"; break;

-			case 113: s = "this symbol not expected in DatatypeDecl"; break;

-			case 114: s = "this symbol not expected in ArbitraryTypeDecl"; break;

-			case 115: s = "invalid ClassMemberDecl"; break;

-			case 116: s = "this symbol not expected in FieldDecl"; break;

+			case 110: s = "invalid SubModuleDecl"; break;

+			case 111: s = "this symbol not expected in ClassDecl"; break;

+			case 112: s = "this symbol not expected in DatatypeDecl"; break;

+			case 113: s = "invalid DatatypeDecl"; break;

+			case 114: s = "this symbol not expected in DatatypeDecl"; break;

+			case 115: s = "this symbol not expected in ArbitraryTypeDecl"; break;

+			case 116: s = "invalid ClassMemberDecl"; break;

 			case 117: s = "this symbol not expected in FieldDecl"; break;

-			case 118: s = "invalid FunctionDecl"; break;

+			case 118: s = "this symbol not expected in FieldDecl"; break;

 			case 119: s = "invalid FunctionDecl"; break;

 			case 120: s = "invalid FunctionDecl"; break;

-			case 121: s = "this symbol not expected in MethodDecl"; break;

-			case 122: s = "invalid MethodDecl"; break;

+			case 121: s = "invalid FunctionDecl"; break;

+			case 122: s = "this symbol not expected in MethodDecl"; break;

 			case 123: s = "invalid MethodDecl"; break;

-			case 124: s = "invalid TypeAndToken"; break;

-			case 125: s = "this symbol not expected in MethodSpec"; break;

+			case 124: s = "invalid MethodDecl"; break;

+			case 125: s = "invalid TypeAndToken"; break;

 			case 126: s = "this symbol not expected in MethodSpec"; break;

 			case 127: s = "this symbol not expected in MethodSpec"; break;

 			case 128: s = "this symbol not expected in MethodSpec"; break;

-			case 129: s = "invalid MethodSpec"; break;

-			case 130: s = "this symbol not expected in MethodSpec"; break;

-			case 131: s = "invalid MethodSpec"; break;

-			case 132: s = "invalid ReferenceType"; break;

-			case 133: s = "this symbol not expected in FunctionSpec"; break;

+			case 129: s = "this symbol not expected in MethodSpec"; break;

+			case 130: s = "invalid MethodSpec"; break;

+			case 131: s = "this symbol not expected in MethodSpec"; break;

+			case 132: s = "invalid MethodSpec"; break;

+			case 133: s = "invalid ReferenceType"; break;

 			case 134: s = "this symbol not expected in FunctionSpec"; break;

 			case 135: s = "this symbol not expected in FunctionSpec"; break;

 			case 136: s = "this symbol not expected in FunctionSpec"; break;

 			case 137: s = "this symbol not expected in FunctionSpec"; break;

-			case 138: s = "invalid FunctionSpec"; break;

-			case 139: s = "invalid PossiblyWildFrameExpression"; break;

-			case 140: s = "invalid PossiblyWildExpression"; break;

-			case 141: s = "this symbol not expected in OneStmt"; break;

-			case 142: s = "invalid OneStmt"; break;

-			case 143: s = "this symbol not expected in OneStmt"; break;

-			case 144: s = "invalid OneStmt"; break;

-			case 145: s = "invalid AssertStmt"; break;

-			case 146: s = "invalid UpdateStmt"; break;

+			case 138: s = "this symbol not expected in FunctionSpec"; break;

+			case 139: s = "invalid FunctionSpec"; break;

+			case 140: s = "invalid PossiblyWildFrameExpression"; break;

+			case 141: s = "invalid PossiblyWildExpression"; break;

+			case 142: s = "this symbol not expected in OneStmt"; break;

+			case 143: s = "invalid OneStmt"; break;

+			case 144: s = "this symbol not expected in OneStmt"; break;

+			case 145: s = "invalid OneStmt"; break;

+			case 146: s = "invalid AssertStmt"; break;

 			case 147: s = "invalid UpdateStmt"; break;

-			case 148: s = "invalid IfStmt"; break;

+			case 148: s = "invalid UpdateStmt"; break;

 			case 149: s = "invalid IfStmt"; break;

-			case 150: s = "invalid WhileStmt"; break;

+			case 150: s = "invalid IfStmt"; break;

 			case 151: s = "invalid WhileStmt"; break;

-			case 152: s = "invalid Rhs"; break;

-			case 153: s = "invalid Lhs"; break;

-			case 154: s = "invalid Guard"; break;

-			case 155: s = "this symbol not expected in LoopSpec"; break;

+			case 152: s = "invalid WhileStmt"; break;

+			case 153: s = "invalid Rhs"; break;

+			case 154: s = "invalid Lhs"; break;

+			case 155: s = "invalid Guard"; break;

 			case 156: s = "this symbol not expected in LoopSpec"; break;

 			case 157: s = "this symbol not expected in LoopSpec"; break;

 			case 158: s = "this symbol not expected in LoopSpec"; break;

 			case 159: s = "this symbol not expected in LoopSpec"; break;

-			case 160: s = "this symbol not expected in Invariant"; break;

-			case 161: s = "invalid AttributeArg"; break;

-			case 162: s = "invalid EquivOp"; break;

-			case 163: s = "invalid ImpliesOp"; break;

-			case 164: s = "invalid AndOp"; break;

-			case 165: s = "invalid OrOp"; break;

-			case 166: s = "invalid RelOp"; break;

-			case 167: s = "invalid AddOp"; break;

-			case 168: s = "invalid UnaryExpression"; break;

-			case 169: s = "invalid MulOp"; break;

-			case 170: s = "invalid NegOp"; break;

-			case 171: s = "invalid EndlessExpression"; break;

-			case 172: s = "invalid Suffix"; break;

+			case 160: s = "this symbol not expected in LoopSpec"; break;

+			case 161: s = "this symbol not expected in Invariant"; break;

+			case 162: s = "invalid AttributeArg"; break;

+			case 163: s = "invalid EquivOp"; break;

+			case 164: s = "invalid ImpliesOp"; break;

+			case 165: s = "invalid AndOp"; break;

+			case 166: s = "invalid OrOp"; break;

+			case 167: s = "invalid RelOp"; break;

+			case 168: s = "invalid AddOp"; break;

+			case 169: s = "invalid UnaryExpression"; break;

+			case 170: s = "invalid MulOp"; break;

+			case 171: s = "invalid NegOp"; break;

+			case 172: s = "invalid EndlessExpression"; break;

 			case 173: s = "invalid Suffix"; break;

 			case 174: s = "invalid Suffix"; break;

-			case 175: s = "invalid DisplayExpr"; break;

-			case 176: s = "invalid MultiSetExpr"; break;

-			case 177: s = "invalid MapExpr"; break;

-			case 178: s = "invalid ConstAtomExpression"; break;

-			case 179: s = "invalid QSep"; break;

-			case 180: s = "invalid QuantifierGuts"; break;

-			case 181: s = "invalid Forall"; break;

-			case 182: s = "invalid Exists"; break;

+			case 175: s = "invalid Suffix"; break;

+			case 176: s = "invalid DisplayExpr"; break;

+			case 177: s = "invalid MultiSetExpr"; break;

+			case 178: s = "invalid MapExpr"; break;

+			case 179: s = "invalid ConstAtomExpression"; break;

+			case 180: s = "invalid QSep"; break;

+			case 181: s = "invalid QuantifierGuts"; break;

+			case 182: s = "invalid Forall"; break;

+			case 183: s = "invalid Exists"; break;

 

 			default: s = "error " + n; break;

 		}

diff --git a/Source/Dafny/Printer.cs b/Source/Dafny/Printer.cs
index fb46ba4b..36883203 100644
--- a/Source/Dafny/Printer.cs
+++ b/Source/Dafny/Printer.cs
@@ -32,7 +32,7 @@ namespace Microsoft.Dafny {
         wr.WriteLine("// " + Bpl.CommandLineOptions.Clo.Environment);

       }

       wr.WriteLine("// {0}", prog.Name);

-      foreach (ModuleDecl module in prog.Modules) {

+      foreach (ModuleDefinition module in prog.Modules) {

         wr.WriteLine();

         if (module.IsDefaultModule) {

           PrintTopLevelDecls(module.TopLevelDecls, 0);

@@ -43,13 +43,6 @@ namespace Microsoft.Dafny {
           if (module.RefinementBaseName != null) {

             wr.Write("refines {0} ", module.RefinementBaseName);

           }

-          if (module.ImportNames.Count != 0) {

-            string sep = "imports ";

-            foreach (string imp in module.ImportNames) {

-              wr.Write("{0}{1}", sep, imp);

-              sep = ", ";

-            }

-          }

           if (module.TopLevelDecls.Count == 0) {

             wr.WriteLine(" { }");

           } else {

@@ -144,14 +137,7 @@ namespace Microsoft.Dafny {
 

       wr.Write(" {0}", name);

       if (typeArgs.Count != 0) {

-        wr.Write("<");

-        string sep = "";

-        foreach (TypeParameter tp in typeArgs) {

-          Contract.Assert(tp != null);

-          wr.Write("{0}{1}", sep, tp.Name);

-          sep = ", ";

-        }

-        wr.Write(">");

+        wr.Write("<" + Util.Comma(", ", typeArgs, tp => tp.Name) + ">");

       }

     }

 

diff --git a/Source/Dafny/RefinementTransformer.cs b/Source/Dafny/RefinementTransformer.cs
index 51b22443..180aecbd 100644
--- a/Source/Dafny/RefinementTransformer.cs
+++ b/Source/Dafny/RefinementTransformer.cs
@@ -21,8 +21,8 @@ using IToken = Microsoft.Boogie.IToken;
 namespace Microsoft.Dafny {

   public class RefinementToken : TokenWrapper

   {

-    public readonly ModuleDecl InheritingModule;

-    public RefinementToken(IToken tok, ModuleDecl m)

+    public readonly ModuleDefinition InheritingModule;

+    public RefinementToken(IToken tok, ModuleDefinition m)

       : base(tok)

     {

       Contract.Requires(tok != null);

@@ -30,7 +30,7 @@ namespace Microsoft.Dafny {
       this.InheritingModule = m;

     }

 

-    public static bool IsInherited(IToken tok, ModuleDecl m) {

+    public static bool IsInherited(IToken tok, ModuleDefinition m) {

       while (tok is NestedToken) {

         var n = (NestedToken)tok;

         // check Outer

@@ -58,29 +58,16 @@ namespace Microsoft.Dafny {
       this.reporter = reporter;

     }

 

-    private ModuleDecl moduleUnderConstruction;  // non-null for the duration of Construct calls

+    private ModuleDefinition moduleUnderConstruction;  // non-null for the duration of Construct calls

 

-    public void Construct(ModuleDecl m) {

+    public void Construct(ModuleDefinition m) {

       Contract.Requires(m != null);

       Contract.Requires(m.RefinementBase != null);

 

       Contract.Assert(moduleUnderConstruction == null);

       moduleUnderConstruction = m;

       var prev = m.RefinementBase;

-

-      // Include the imports of the base.  Note, prev is itself NOT added as an import

-      // of m; instead, the contents from prev is merged directly into m.

-      // (Here, we change the import declarations.  But edges for these imports will

-      // not be added to the importGraph of the calling resolver.  However, the refines

-      // clause gave rise to an edge in the importGraph, so the transitive import edges

-      // are represented in the importGraph.)

-      foreach (var im in prev.Imports) {

-        if (!m.ImportNames.Contains(im.Name)) {

-          m.ImportNames.Add(im.Name);

-          m.Imports.Add(im);

-        }

-      }

-

+      

       // Create a simple name-to-decl dictionary.  Ignore any duplicates at this time.

       var declaredNames = new Dictionary<string, int>();

       for (int i = 0; i < m.TopLevelDecls.Count; i++) {

@@ -91,15 +78,26 @@ namespace Microsoft.Dafny {
       }

 

       // Merge the declarations of prev into the declarations of m

-

       foreach (var d in prev.TopLevelDecls) {

         int index;

         if (!declaredNames.TryGetValue(d.Name, out index)) {

           m.TopLevelDecls.Add(CloneDeclaration(d, m));

         } else {

           var nw = m.TopLevelDecls[index];

-          if (d is ArbitraryTypeDecl) {

+          if (d is ModuleDecl) {

+            if (!(nw is ModuleDecl)) {

+              reporter.Error(nw, "a module ({0}) must refine another module", nw.Name);

+            }

+            if (d is AliasModuleDecl || d is LiteralModuleDecl) {

+              reporter.Error(nw, "a module ({0}) can only refine abstract modules", nw.Name);

+            }

+          } else if (d is ArbitraryTypeDecl) {

             // this is allowed to be refined by any type declaration, so just keep the new one

+            // of course, the new thing has to be a type. Everything is a type except for a module

+            // declaration

+            if (nw is ModuleDecl) {

+              reporter.Error(nw, "a module ({0}) must refine another module", nw.Name);

+            }

           } else if (nw is ArbitraryTypeDecl) {

             reporter.Error(nw, "an arbitrary type declaration ({0}) in a refining module cannot replace a more specific type declaration in the refinement base", nw.Name);

           } else if (nw is DatatypeDecl) {

@@ -129,7 +127,8 @@ namespace Microsoft.Dafny {
 

     // -------------------------------------------------- Cloning ---------------------------------------------------------------

 

-    TopLevelDecl CloneDeclaration(TopLevelDecl d, ModuleDecl m) {

+    // Clone a toplevel, specifying that its parent module should be m (i.e. it will be added to m.TopLevelDecls).

+    TopLevelDecl CloneDeclaration(TopLevelDecl d, ModuleDefinition m) {

       Contract.Requires(d != null);

       Contract.Requires(m != null);

 

@@ -154,6 +153,22 @@ namespace Microsoft.Dafny {
         var mm = dd.Members.ConvertAll(CloneMember);

         var cl = new ClassDecl(Tok(dd.tok), dd.Name, m, tps, mm, null);

         return cl;

+      } else if (d is ModuleDecl) {

+        if (d is LiteralModuleDecl) {

+          return new LiteralModuleDecl(((LiteralModuleDecl)d).ModuleDef,m);

+        } else if (d is AliasModuleDecl) {

+          var a = (AliasModuleDecl)d;

+          var alias = new AliasModuleDecl(a.Path, a.tok, m);

+          alias.ModuleReference = a.ModuleReference;

+          alias.Signature = a.Signature;

+          return alias;

+        } else if (d is AbstractModuleDecl) {

+          var a = (AbstractModuleDecl)d;

+          return new AbstractModuleDecl(a.Path, a.tok, m);

+        } else {

+          Contract.Assert(false);  // unexpected declaration

+          return null;  // to please compiler

+        }

       } else {

         Contract.Assert(false);  // unexpected declaration

         return null;  // to please compiler

@@ -1120,7 +1135,7 @@ namespace Microsoft.Dafny {
 

     // ---------------------- additional methods -----------------------------------------------------------------------------

 

-    public static bool ContainsChange(Expression expr, ModuleDecl m) {

+    public static bool ContainsChange(Expression expr, ModuleDefinition m) {

       Contract.Requires(expr != null);

       Contract.Requires(m != null);

 

diff --git a/Source/Dafny/Resolver.cs b/Source/Dafny/Resolver.cs
index 22a0a299..63f2f9e9 100644
--- a/Source/Dafny/Resolver.cs
+++ b/Source/Dafny/Resolver.cs
@@ -65,13 +65,13 @@ namespace Microsoft.Dafny {
 

     //Dictionary<string/*!*/,TopLevelDecl/*!*/>/*!*/ classes;  // can map to AmbiguousTopLevelDecl

     //Dictionary<string, ModuleDecl> importedNames; // the imported modules, as a map.

-    ModuleNameInformation moduleInfo = null;

+    ModuleSignature moduleInfo = null;

 

     class AmbiguousTopLevelDecl : TopLevelDecl  // only used with "classes"

     {

       readonly TopLevelDecl A;

       readonly TopLevelDecl B;

-      public AmbiguousTopLevelDecl(ModuleDecl m, TopLevelDecl a, TopLevelDecl b)

+      public AmbiguousTopLevelDecl(ModuleDefinition m, TopLevelDecl a, TopLevelDecl b)

         : base(a.tok, a.Name + "/" + b.Name, m, new List<TypeParameter>(), null) {

         A = a;

         B = b;

@@ -96,8 +96,7 @@ namespace Microsoft.Dafny {
     readonly Dictionary<ClassDecl/*!*/, Dictionary<string/*!*/, MemberDecl/*!*/>/*!*/>/*!*/ classMembers = new Dictionary<ClassDecl/*!*/, Dictionary<string/*!*/, MemberDecl/*!*/>/*!*/>();

     readonly Dictionary<DatatypeDecl/*!*/, Dictionary<string/*!*/, MemberDecl/*!*/>/*!*/>/*!*/ datatypeMembers = new Dictionary<DatatypeDecl/*!*/, Dictionary<string/*!*/, MemberDecl/*!*/>/*!*/>();

     readonly Dictionary<DatatypeDecl/*!*/, Dictionary<string/*!*/, DatatypeCtor/*!*/>/*!*/>/*!*/ datatypeCtors = new Dictionary<DatatypeDecl/*!*/, Dictionary<string/*!*/, DatatypeCtor/*!*/>/*!*/>();

-    readonly Graph<ModuleDecl/*!*/>/*!*/ importGraph = new Graph<ModuleDecl/*!*/>();

-    private ModuleNameInformation[] moduleNameInfo;

+    readonly Graph<ModuleDecl/*!*/>/*!*/ dependencies = new Graph<ModuleDecl/*!*/>();

     public Resolver(Program prog) {

       Contract.Requires(prog != null);

       builtIns = prog.BuiltIns;

@@ -106,66 +105,109 @@ namespace Microsoft.Dafny {
     [ContractInvariantMethod]

     void ObjectInvariant() {

       Contract.Invariant(builtIns != null);

-      Contract.Invariant(cce.NonNullElements(importGraph));

+      Contract.Invariant(cce.NonNullElements(dependencies));

       Contract.Invariant(cce.NonNullDictionaryAndValues(classMembers) && Contract.ForAll(classMembers.Values, v => cce.NonNullDictionaryAndValues(v)));

       Contract.Invariant(cce.NonNullDictionaryAndValues(datatypeCtors) && Contract.ForAll(datatypeCtors.Values, v => cce.NonNullDictionaryAndValues(v)));

     }

 

     public void ResolveProgram(Program prog) {

       Contract.Requires(prog != null);

-

-      BindModuleNames(prog.DefaultModule, new ModuleBindings(null), prog.Modules, importGraph);

-

+      var bindings = new ModuleBindings(null);

+      var b = BindModuleNames(prog.DefaultModuleDef, bindings);

+      bindings.BindName("_module", prog.DefaultModule , b);

+      if (ErrorCount > 0) { return; } // if there were errors, then the implict ModuleBindings data structure invariant

+                                      // is violated, so Processing dependencies will not succeed.

+      ProcessDependencies(prog.DefaultModule, b, dependencies);

       // check for cycles in the import graph

-      List<ModuleDecl> cycle = importGraph.TryFindCycle();

+      List<ModuleDecl> cycle = dependencies.TryFindCycle();

       if (cycle != null) {

-        string cy = "";

-        string sep = "";

-        foreach (ModuleDecl m in cycle) {

-          cy = m.Name + sep + cy;

-          sep = " -> ";

-        }

-        Error(cycle[0], "import graph contains a cycle (note: parent modules implicitly depend on submodules): {0}", cy);

-        return;  // give up on trying to resolve anything else

+        var cy = Util.Comma(" -> ", cycle, m => m.Name);

+        Error(cycle[0], "module definition contains a cycle (note: parent modules implicitly depend on submodules): {0}", cy);

       }

+      if (ErrorCount > 0) { return; } // give up on trying to resolve anything else

 

       // fill in module heights

-      List<ModuleDecl> mm = importGraph.TopologicallySortedComponents();

-      Contract.Assert(mm.Count == prog.Modules.Count);  // follows from the fact that there are no cycles

+      List<ModuleDecl> sortedDecls = dependencies.TopologicallySortedComponents();

       int h = 0;

-      foreach (ModuleDecl m in mm) {

+      foreach (ModuleDecl m in sortedDecls) {

         m.Height = h;

+        if (m is LiteralModuleDecl) {

+          var mdef = ((LiteralModuleDecl)m).ModuleDef;

+          mdef.Height = h;

+          prog.Modules.Add(mdef);

+        }

         h++;

       }

+      var mm = prog.Modules;

       // register top-level declarations

-      Rewriter rewriter = new AutoContractsRewriter();

-      var systemNameInfo = RegisterTopLevelDecls(prog.BuiltIns.SystemModule.TopLevelDecls);

-      moduleNameInfo = new ModuleNameInformation[h];

-      foreach (var m in mm) {

-        rewriter.PreResolve(m);

-        if (m.RefinementBase != null) {

-          var transformer = new RefinementTransformer(this);

-          transformer.Construct(m);

-        }

-        moduleNameInfo[m.Height] = RegisterTopLevelDecls(m.TopLevelDecls);

-        // set up environment

-        moduleInfo = ModuleNameInformation.Merge(m, systemNameInfo, moduleNameInfo);

-        /*

-        classes = info.Classes;

-        importedNames = info.ImportedNames;

-        allDatatypeCtors = info.Ctors;

-        */

-        // resolve

-        var datatypeDependencies = new Graph<IndDatatypeDecl>();

-        ResolveTopLevelDecls_Signatures(m.TopLevelDecls, datatypeDependencies);

-        ResolveTopLevelDecls_Meat(m.TopLevelDecls, datatypeDependencies);

-        // tear down

-        // give rewriter a chance to do processing

-        rewriter.PostResolve(m);

+      

+      //Rewriter rewriter = new AutoContractsRewriter();

+      var systemNameInfo = RegisterTopLevelDecls(prog.BuiltIns.SystemModule);

+      foreach (var decl in sortedDecls) {

+        if (decl is LiteralModuleDecl) {

+          // The declaration is a literal module, so it has members and such that we need

+          // to resolve. First we do refinement transformation. Then we construct the signature

+          // of the module. This is the public, externally visible signature. Then we add in 

+          // everything that the system defines, as well as any "import" (i.e. "opened" modules)

+          // directives (currently not supported, but this is where we would do it.) This signature,

+          // which is only used while resolving the members of the module is stored in the (basically)

+          // global variable moduleInfo. Then the signatures of the module members are resolved, followed

+          // by the bodies.

+          var literalDecl = (LiteralModuleDecl)decl;

+          var m = (literalDecl).ModuleDef;

+          //rewriter.PreResolve(m);

+          if (m.RefinementBaseRoot != null) {

+            ModuleSignature sig;

+            if (ResolvePath(m.RefinementBaseRoot, m.RefinementBaseName, out sig)) {

+              if (sig.ModuleDef != null) {

+                m.RefinementBase = sig.ModuleDef;

+                var transformer = new RefinementTransformer(this);

+                transformer.Construct(m);

+              } else {

+                Error(m.RefinementBaseName[0], "module ({0}) named as refinement base is not a literal module or reference to a literal module", Util.Comma(".", m.RefinementBaseName, x => x.val));

+              }

+            } else {

+              Error(m.RefinementBaseName[0], "module ({0}) named as refinement base does not exist", Util.Comma(".", m.RefinementBaseName, x => x.val));

+            }

+          }

+          literalDecl.Signature = RegisterTopLevelDecls(m);

+          // set up environment

+          moduleInfo = MergeSignature(literalDecl.Signature, systemNameInfo);

+          // resolve

+          var datatypeDependencies = new Graph<IndDatatypeDecl>();

+          ResolveTopLevelDecls_Signatures(m.TopLevelDecls, datatypeDependencies);

+          ResolveTopLevelDecls_Meat(m.TopLevelDecls, datatypeDependencies);

+          // give rewriter a chance to do processing

+          //rewriter.PostResolve(m);

+        } else if (decl is AliasModuleDecl) {

+          var alias = (AliasModuleDecl)decl;

+          // resolve the path

+          ModuleSignature p;

+          if (ResolvePath(alias.Root, alias.Path, out p)) {

+            alias.Signature = p;

+          } else {

+            alias.Signature = new ModuleSignature(); // there was an error, give it a valid but empty signature

+          }

+        } else if (decl is AbstractModuleDecl) {

+          var abs = (AbstractModuleDecl)decl;

+          ModuleSignature p; ModuleDefinition mod;

+          if (ResolvePath(abs.Root, abs.Path, out p)) {

+            abs.Signature = MakeAbstractSignature(p, abs.Name, abs.Height, out mod);

+            moduleInfo = MergeSignature(abs.Signature, systemNameInfo);

+            // resolve

+            var datatypeDependencies = new Graph<IndDatatypeDecl>();

+            ResolveTopLevelDecls_Signatures(mod.TopLevelDecls, datatypeDependencies);

+            ResolveTopLevelDecls_Meat(mod.TopLevelDecls, datatypeDependencies);

+            prog.Modules.Add(mod);

+          } else {

+            abs.Signature = new ModuleSignature(); // there was an error, give it a valid but empty signature

+          }

+        } else { Contract.Assert(false); }

+        Contract.Assert(decl.Signature != null);

       }

 

       // compute IsRecursive bit for mutually recursive functions

-      foreach (ModuleDecl m in mm) {

+      foreach (ModuleDefinition m in mm) {

         foreach (TopLevelDecl decl in m.TopLevelDecls) {

           ClassDecl cl = decl as ClassDecl;

           if (cl != null) {

@@ -182,152 +224,153 @@ namespace Microsoft.Dafny {
           }

         }

       }

+      

     }

 

-    private class ModuleBindings {

+

+    public class ModuleBindings {

       private ModuleBindings parent;

       private Dictionary<string, ModuleDecl> modules;

+      private Dictionary<string, ModuleBindings> bindings;

 

       public ModuleBindings(ModuleBindings p) {

         parent = p;

-        modules = new Dictionary<string,ModuleDecl>();

+        modules = new Dictionary<string, ModuleDecl>();

+        bindings = new Dictionary<string, ModuleBindings>();

       }

-      public bool BindName(string name, ModuleDecl subModule) {

+      public bool BindName(string name, ModuleDecl subModule, ModuleBindings b) {

         if (modules.ContainsKey(name)) {

           return false;

         } else {

           modules.Add(name, subModule);

+          bindings.Add(name, b);

           return true;

         }

       }

-      public bool TryLookup(string name, out ModuleDecl m) {

-        if (modules.TryGetValue(name, out m))

+      public bool TryLookup(IToken name, out ModuleDecl m) {

+        Contract.Requires(name != null);

+        if (modules.TryGetValue(name.val, out m)) {

           return true;

-        else if (parent != null) {

+        } else if (parent != null) {

           return parent.TryLookup(name, out m);

         } else return false;

       }

+      public IEnumerable<ModuleDecl> ModuleList {

+        get { return modules.Values; }

+      }

+      public ModuleBindings SubBindings(string name) {

+        ModuleBindings v = null;

+        bindings.TryGetValue(name, out v);

+        return v;

+      }

     }

-    private void BindModuleNames(ModuleDecl moduleDecl, ModuleBindings parentBindings, List<ModuleDecl> globalModuleList, Graph<ModuleDecl> importGraph) {

-      // a dictionary of submodules at the current scope.

-      var modules = new Dictionary<string, ModuleDecl>();

-      var moduleList = new List<ModuleDecl>();

+    private ModuleBindings BindModuleNames(ModuleDefinition moduleDecl, ModuleBindings parentBindings) {

       var bindings = new ModuleBindings(parentBindings);

+

       foreach (var tld in moduleDecl.TopLevelDecls) {

-        var submodule = tld as SubModuleDecl;

-        if (submodule != null) {

-          var name = submodule.SubModule.Name;

-          if (!bindings.BindName(name, submodule.SubModule)) {

-            Error(submodule.Module, "Duplicate module name: {0}", name);

-          } else {

-            moduleList.Add(submodule.SubModule);

+        if (tld is LiteralModuleDecl) {

+          var subdecl = (LiteralModuleDecl)tld;

+          var subBindings = BindModuleNames(subdecl.ModuleDef, bindings);

+          subdecl.ModuleDef.Bindings = subBindings;

+          if (!bindings.BindName(subdecl.Name, subdecl, subBindings)) {

+            Error(subdecl.Module, "Duplicate module name: {0}", subdecl.Name);

           }

-        }

-      }

-      

-      // resolve refines and imports

-      foreach (var m in moduleList) {

-        importGraph.AddVertex(m);

-        if (m.RefinementBaseName != null) {

-          ModuleDecl other;

-          if (!bindings.TryLookup(m.RefinementBaseName, out other)) {

-            Error(m, "module {0} named as refinement base does not exist", m.RefinementBaseName);

-          } else if (other == m) {

-            Error(m, "module cannot refine itself: {0}", m.RefinementBaseName);

-          } else {

-            Contract.Assert(other != null);  // follows from postcondition of TryGetValue

-            importGraph.AddEdge(m, other);

-            m.RefinementBase = other;

+        } else if (tld is AbstractModuleDecl) {

+          var subdecl = (AbstractModuleDecl)tld;

+          if (!bindings.BindName(subdecl.Name, subdecl, null)) {

+            Error(subdecl.Module, "Duplicate module name: {0}", subdecl.Name);

           }

-        }

-        foreach (string imp in m.ImportNames) {

-          ModuleDecl other;

-          if (!bindings.TryLookup(imp, out other)) {

-            Error(m, "module {0} named among imports does not exist", imp);

-          } else if (other == m) {

-            Error(m, "module must not import itself: {0}", imp);

-          } else {

-            Contract.Assert(other != null);  // follows from postcondition of TryGetValue

-            importGraph.AddEdge(m, other);

-            m.Imports.Add(other);

+        } else if (tld is AliasModuleDecl) {

+          var subdecl = (AliasModuleDecl)tld;

+          if (!bindings.BindName(subdecl.Name, subdecl, null)) {

+            Error(subdecl.Module, "Duplicate module name: {0}", subdecl.Name);

           }

         }

-        foreach (var dep in m.Dependencies) {

-          importGraph.AddEdge(m, dep);

-        }

-      }

-      foreach (var m in moduleList) {

-        BindModuleNames(m, bindings, globalModuleList, importGraph);

       }

-      globalModuleList.AddRange(moduleList);

+      return bindings;

     }

 

-    public class ModuleNameInformation

-    {

-      public readonly Dictionary<string, TopLevelDecl> Classes = new Dictionary<string, TopLevelDecl>();

-      public readonly Dictionary<string, ModuleDecl> ImportedNames = new Dictionary<string, ModuleDecl>();

-      public readonly Dictionary<string, Tuple<DatatypeCtor, bool>> Ctors = new Dictionary<string,Tuple<DatatypeCtor,bool>>();

-

-      public static ModuleNameInformation Merge(ModuleDecl m, ModuleNameInformation system, ModuleNameInformation[] modules) {

-        var info = new ModuleNameInformation();

-        // add the system-declared information, among which we know there are no duplicates

-        foreach (var kv in system.Classes) {

-          info.Classes.Add(kv.Key, kv.Value);

-        }

-        foreach (var kv in system.Ctors) {

-          info.Ctors.Add(kv.Key, kv.Value);

-        }

-        // for each imported module, add its information, noting any duplicates

-        foreach (var im in m.Imports) {

-          Contract.Assume(0 <= im.Height && im.Height < m.Height);

-          var import = modules[im.Height];

-          info.ImportedNames.Add(im.Name, im);

-          // classes:

-          foreach (var kv in import.Classes) {

-            TopLevelDecl d;

-            if (info.Classes.TryGetValue(kv.Key, out d)) {

-              info.Classes[kv.Key] = new AmbiguousTopLevelDecl(m, d, kv.Value);

-            } else {

-              info.Classes.Add(kv.Key, kv.Value);

-            }

-          }

-          // constructors:

-          foreach (var kv in import.Ctors) {

-            Tuple<DatatypeCtor, bool> pair;

-            if (info.Ctors.TryGetValue(kv.Key, out pair)) {

-              // mark it as a duplicate

-              info.Ctors[kv.Key] = new Tuple<DatatypeCtor, bool>(pair.Item1, true);

-            } else {

-              // add new

-              info.Ctors.Add(kv.Key, kv.Value);

-            }

-          }

+    private void ProcessDependenciesDefinition(ModuleDecl decl, ModuleDefinition m, ModuleBindings bindings, Graph<ModuleDecl> dependencies) {

+      if (m.RefinementBaseName != null) {

+        ModuleDecl other;

+        if (!bindings.TryLookup(m.RefinementBaseName[0], out other)) {

+          Error(m, "module {0} named as refinement base does not exist", m.RefinementBaseName[0].val);

+        } else if (other is LiteralModuleDecl && ((LiteralModuleDecl)other).ModuleDef == m) {

+          Error(m, "module cannot refine itself: {0}", m.RefinementBaseName[0].val);

+        } else {

+          Contract.Assert(other != null);  // follows from postcondition of TryGetValue

+          dependencies.AddEdge(decl, other);

+          m.RefinementBaseRoot = other;

         }

-        // finally, for the module itself, let its information override whatever is imported

-        foreach (var kv in modules[m.Height].Classes) {

-          info.Classes[kv.Key] = kv.Value;

+      }

+      foreach (var toplevel in m.TopLevelDecls) {

+        if (toplevel is ModuleDecl) {

+          var d = (ModuleDecl)toplevel;

+          dependencies.AddEdge(decl, d);

+          var subbindings = bindings.SubBindings(d.Name);

+          ProcessDependencies(d, subbindings ?? bindings, dependencies);

         }

-        foreach (var kv in modules[m.Height].Ctors) {

-          info.Ctors[kv.Key] = kv.Value;

+      }

+    }

+    private void ProcessDependencies(ModuleDecl moduleDecl, ModuleBindings bindings, Graph<ModuleDecl> dependencies) {

+      // resolve refines and imports

+      if (moduleDecl is LiteralModuleDecl) {

+        ProcessDependenciesDefinition(moduleDecl, ((LiteralModuleDecl)moduleDecl).ModuleDef, bindings, dependencies);

+      } else if (moduleDecl is AliasModuleDecl) {

+        var alias = moduleDecl as AliasModuleDecl;

+        ModuleDecl root;

+        if (!bindings.TryLookup(alias.Path[0], out root))

+          Error(alias.tok, "module {0} does not exist", Util.Comma(".", alias.Path, x => x.val));

+        else {

+          dependencies.AddEdge(moduleDecl, root);

+          alias.Root = root;

+        }

+      } else if (moduleDecl is AbstractModuleDecl) {

+        var abs = moduleDecl as AbstractModuleDecl;

+        ModuleDecl root;

+        if (!bindings.TryLookup(abs.Path[0], out root))

+          Error(abs.tok, "module {0} does not exist", Util.Comma(".", abs.Path, x => x.val));

+        else {

+          dependencies.AddEdge(moduleDecl, root);

+          abs.Root = root;

         }

-        return info;

       }

     }

 

-    ModuleNameInformation RegisterTopLevelDecls(List<TopLevelDecl> declarations) {

-      Contract.Requires(declarations != null);

-      var info = new ModuleNameInformation();

+    public static ModuleSignature MergeSignature(ModuleSignature m, ModuleSignature system) {

+      var info = new ModuleSignature();

+      // add the system-declared information, among which we know there are no duplicates

+      foreach (var kv in system.TopLevels) {

+        info.TopLevels.Add(kv.Key, kv.Value);

+      }

+      foreach (var kv in system.Ctors) {

+        info.Ctors.Add(kv.Key, kv.Value);

+      }

+      // add for the module itself

+      foreach (var kv in m.TopLevels) {

+        info.TopLevels[kv.Key] = kv.Value;

+      }

+      foreach (var kv in m.Ctors) {

+        info.Ctors[kv.Key] = kv.Value;

+      }

+      return info;

+    }

+    ModuleSignature RegisterTopLevelDecls(ModuleDefinition moduleDef) {

+      Contract.Requires(moduleDef != null);

+      var sig = new ModuleSignature();

+      sig.ModuleDef = moduleDef;

+      List<TopLevelDecl> declarations = moduleDef.TopLevelDecls;

 

       foreach (TopLevelDecl d in declarations) {

         Contract.Assert(d != null);

-        // register the class/datatype name

-        if (info.Classes.ContainsKey(d.Name)) {

+        // register the class/datatype/module name

+        if (sig.TopLevels.ContainsKey(d.Name)) {

           Error(d, "Duplicate name of top-level declaration: {0}", d.Name);

         } else {

-          info.Classes.Add(d.Name, d);

+          sig.TopLevels.Add(d.Name, d);

         }

-        if (d is SubModuleDecl) {

-          // do Nothing 

+        if (d is ModuleDecl) {

+          // nothing to do

         } else if (d is ArbitraryTypeDecl) {

           // nothing more to register

 

@@ -378,12 +421,12 @@ namespace Microsoft.Dafny {
 

               // also register the constructor name globally

               Tuple<DatatypeCtor, bool> pair;

-              if (info.Ctors.TryGetValue(ctor.Name, out pair)) {

+              if (sig.Ctors.TryGetValue(ctor.Name, out pair)) {

                 // mark it as a duplicate

-                info.Ctors[ctor.Name] = new Tuple<DatatypeCtor, bool>(pair.Item1, true);

+                sig.Ctors[ctor.Name] = new Tuple<DatatypeCtor, bool>(pair.Item1, true);

               } else {

                 // add new

-                info.Ctors.Add(ctor.Name, new Tuple<DatatypeCtor, bool>(ctor, false));

+                sig.Ctors.Add(ctor.Name, new Tuple<DatatypeCtor, bool>(ctor, false));

               }

             }

           }

@@ -405,9 +448,331 @@ namespace Microsoft.Dafny {
           }

         }

       }

-      return info;

+      return sig;

+    }

+

+    private ModuleSignature MakeAbstractSignature(ModuleSignature p, string Name, int Height, out ModuleDefinition mod) {

+      mod = new ModuleDefinition(Token.NoToken, Name+".Abs", true, true, null, null);

+      mod.Height = Height;

+      foreach (var kv in p.TopLevels) {

+        mod.TopLevelDecls.Add(CloneDeclaration(kv.Value, mod));

+      }

+      return RegisterTopLevelDecls(mod);

+    }

+    TopLevelDecl CloneDeclaration(TopLevelDecl d, ModuleDefinition m) {

+      Contract.Requires(d != null);

+      Contract.Requires(m != null);

+

+      if (d is ArbitraryTypeDecl) {

+        var dd = (ArbitraryTypeDecl)d;

+        return new ArbitraryTypeDecl(dd.tok, dd.Name, m, null);

+      } else if (d is IndDatatypeDecl) {

+        var dd = (IndDatatypeDecl)d;

+        var tps = dd.TypeArgs.ConvertAll(CloneTypeParam);

+        var ctors = dd.Ctors.ConvertAll(CloneCtor);

+        var dt = new IndDatatypeDecl(dd.tok, dd.Name, m, tps, ctors, null);

+        return dt;

+      } else if (d is CoDatatypeDecl) {

+        var dd = (CoDatatypeDecl)d;

+        var tps = dd.TypeArgs.ConvertAll(CloneTypeParam);

+        var ctors = dd.Ctors.ConvertAll(CloneCtor);

+        var dt = new CoDatatypeDecl(dd.tok, dd.Name, m, tps, ctors, null);

+        return dt;

+      } else if (d is ClassDecl) {

+        var dd = (ClassDecl)d;

+        var tps = dd.TypeArgs.ConvertAll(CloneTypeParam);

+        var mm = dd.Members.ConvertAll(CloneMember);

+        var cl = new ClassDecl(dd.tok, dd.Name, m, tps, mm, null);

+        return cl;

+      } else if (d is ModuleDecl) {

+        if (d is LiteralModuleDecl) {

+          return new LiteralModuleDecl(((LiteralModuleDecl)d).ModuleDef, m);

+        } else if (d is AliasModuleDecl) {

+          var a = (AliasModuleDecl)d;

+          var alias = new AliasModuleDecl(a.Path, a.tok, m);

+          alias.ModuleReference = a.ModuleReference;

+          alias.Signature = a.Signature;

+          return alias;

+        }

+        Contract.Assert(false);  // unexpected declaration

+        return null;  // to please compiler

+      } else {

+        Contract.Assert(false);  // unexpected declaration

+        return null;  // to please compiler

+      }

+    }

+    MemberDecl CloneMember(MemberDecl member) {

+      if (member is Field) {

+        var f = (Field)member;

+        return new Field(f.tok, f.Name, f.IsGhost, f.IsMutable, CloneType(f.Type), null);

+      } else if (member is Function) {

+        var f = (Function)member;

+        return CloneFunction(f.tok, f, f.IsGhost);

+      } else {

+        var m = (Method)member;

+        return CloneMethod(m);

+      }

+    }

+    TypeParameter CloneTypeParam(TypeParameter tp) {

+      return new TypeParameter(tp.tok, tp.Name);

+    }

+

+    DatatypeCtor CloneCtor(DatatypeCtor ct) {

+      return new DatatypeCtor(ct.tok, ct.Name, ct.Formals.ConvertAll(CloneFormal), null);

+    }

+    Formal CloneFormal(Formal formal) {

+      return new Formal(formal.tok, formal.Name, CloneType(formal.Type), formal.InParam, formal.IsGhost);

+    }

+    Type CloneType(Type t) {

+      if (t is BasicType) { 

+        return t;

+      } else if (t is SetType) {

+        var tt = (SetType)t;

+        return new SetType(CloneType(tt.Arg));

+      } else if (t is SeqType) {

+        var tt = (SeqType)t;

+        return new SeqType(CloneType(tt.Arg));

+      } else if (t is MultiSetType) {

+        var tt = (MultiSetType)t;

+        return new MultiSetType(CloneType(tt.Arg));

+      } else if (t is MapType) {

+        var tt = (MapType)t;

+        return new MapType(CloneType(tt.Domain), CloneType(tt.Range));

+      } else if (t is UserDefinedType) {

+        var tt = (UserDefinedType)t;

+        return new UserDefinedType(tt.tok, tt.Name, tt.TypeArgs.ConvertAll(CloneType), tt.ModuleName == null ? null : tt.ModuleName);

+      } else if (t is InferredTypeProxy) {

+        return new InferredTypeProxy();

+      } else {

+        Contract.Assert(false);  // unexpected type (e.g., no other type proxies are expected at this time)

+        return null;  // to please compiler

+      }

+    }

+    Function CloneFunction(IToken tok, Function f, bool isGhost) {

+

+      var tps = f.TypeArgs.ConvertAll(CloneTypeParam);

+      var formals = f.Formals.ConvertAll(CloneFormal);

+      var req = f.Req.ConvertAll(CloneExpr);

+      var reads = f.Reads.ConvertAll(CloneFrameExpr);

+      var decreases = CloneSpecExpr(f.Decreases);

+

+      var ens = f.Ens.ConvertAll(CloneExpr);

+

+      Expression body = CloneExpr(f.Body);

+      

+      if (f is Predicate) {

+        return new Predicate(tok, f.Name, f.IsStatic, isGhost, tps, f.OpenParen, formals,

+          req, reads, ens, decreases, body, false, null, false);

+      } else {

+        return new Function(tok, f.Name, f.IsStatic, isGhost, tps, f.OpenParen, formals, CloneType(f.ResultType),

+          req, reads, ens, decreases, body, null, false);

+      }

+    }

+    Method CloneMethod(Method m) {

+      Contract.Requires(m != null);

+

+      var tps = m.TypeArgs.ConvertAll(CloneTypeParam);

+      var ins = m.Ins.ConvertAll(CloneFormal);

+      var req = m.Req.ConvertAll(CloneMayBeFreeExpr);

+      var mod = CloneSpecFrameExpr(m.Mod);

+      var decreases = CloneSpecExpr(m.Decreases);

+

+      var ens = m.Ens.ConvertAll(CloneMayBeFreeExpr);

+      

+      if (m is Constructor) {

+        return new Constructor(m.tok, m.Name, tps, ins,

+          req, mod, ens, decreases, null, null, false);

+      } else {

+        return new Method(m.tok, m.Name, m.IsStatic, m.IsGhost, tps, ins, m.Outs.ConvertAll(CloneFormal),

+          req, mod, ens, decreases, null, null, false);

+      }

+    }

+    Specification<Expression> CloneSpecExpr(Specification<Expression> spec) {

+      var ee = spec.Expressions == null ? null : spec.Expressions.ConvertAll(CloneExpr);

+      return new Specification<Expression>(ee, null);

+    }

+    Specification<FrameExpression> CloneSpecFrameExpr(Specification<FrameExpression> frame) {

+      var ee = frame.Expressions == null ? null : frame.Expressions.ConvertAll(CloneFrameExpr);

+      return new Specification<FrameExpression>(ee, null);

+    }

+    FrameExpression CloneFrameExpr(FrameExpression frame) {

+      return new FrameExpression(CloneExpr(frame.E), frame.FieldName);

+    }

+    MaybeFreeExpression CloneMayBeFreeExpr(MaybeFreeExpression expr) {

+      return new MaybeFreeExpression(CloneExpr(expr.E), expr.IsFree);

+    }

+    BoundVar CloneBoundVar(BoundVar bv) {

+      return new BoundVar((bv.tok), bv.Name, CloneType(bv.Type));

+    }

+    Expression CloneExpr(Expression expr) {

+      if (expr == null) {

+        return null;

+      } else if (expr is LiteralExpr) {

+        var e = (LiteralExpr)expr;

+        if (e.Value == null) {

+          return new LiteralExpr((e.tok));

+        } else if (e.Value is bool) {

+          return new LiteralExpr((e.tok), (bool)e.Value);

+        } else {

+          return new LiteralExpr((e.tok), (BigInteger)e.Value);

+        }

+

+      } else if (expr is ThisExpr) {

+        if (expr is ImplicitThisExpr) {

+          return new ImplicitThisExpr((expr.tok));

+        } else {

+          return new ThisExpr((expr.tok));

+        }

+

+      } else if (expr is IdentifierExpr) {

+        var e = (IdentifierExpr)expr;

+        return new IdentifierExpr((e.tok), e.Name);

+

+      } else if (expr is DatatypeValue) {

+        var e = (DatatypeValue)expr;

+        return new DatatypeValue((e.tok), e.DatatypeName, e.MemberName, e.Arguments.ConvertAll(CloneExpr));

+

+      } else if (expr is DisplayExpression) {

+        DisplayExpression e = (DisplayExpression)expr;

+        if (expr is SetDisplayExpr) {

+          return new SetDisplayExpr((e.tok), e.Elements.ConvertAll(CloneExpr));

+        } else if (expr is MultiSetDisplayExpr) {

+          return new MultiSetDisplayExpr((e.tok), e.Elements.ConvertAll(CloneExpr));

+        } else {

+          Contract.Assert(expr is SeqDisplayExpr);

+          return new SeqDisplayExpr((e.tok), e.Elements.ConvertAll(CloneExpr));

+        }

+

+      } else if (expr is MapDisplayExpr) {

+        MapDisplayExpr e = (MapDisplayExpr)expr;

+        List<ExpressionPair> pp = new List<ExpressionPair>();

+        foreach (ExpressionPair p in e.Elements) {

+          pp.Add(new ExpressionPair(CloneExpr(p.A), CloneExpr(p.B)));

+        }

+        return new MapDisplayExpr((expr.tok), pp);

+      } else if (expr is ExprDotName) {

+        var e = (ExprDotName)expr;

+        return new ExprDotName((e.tok), CloneExpr(e.Obj), e.SuffixName);

+

+      } else if (expr is FieldSelectExpr) {

+        var e = (FieldSelectExpr)expr;

+        return new FieldSelectExpr((e.tok), CloneExpr(e.Obj), e.FieldName);

+

+      } else if (expr is SeqSelectExpr) {

+        var e = (SeqSelectExpr)expr;

+        return new SeqSelectExpr((e.tok), e.SelectOne, CloneExpr(e.Seq), CloneExpr(e.E0), CloneExpr(e.E1));

+

+      } else if (expr is MultiSelectExpr) {

+        var e = (MultiSelectExpr)expr;

+        return new MultiSelectExpr((e.tok), CloneExpr(e.Array), e.Indices.ConvertAll(CloneExpr));

+

+      } else if (expr is SeqUpdateExpr) {

+        var e = (SeqUpdateExpr)expr;

+        return new SeqUpdateExpr((e.tok), CloneExpr(e.Seq), CloneExpr(e.Index), CloneExpr(e.Value));

+

+      } else if (expr is FunctionCallExpr) {

+        var e = (FunctionCallExpr)expr;

+        return new FunctionCallExpr((e.tok), e.Name, CloneExpr(e.Receiver), e.OpenParen == null ? null : (e.OpenParen), e.Args.ConvertAll(CloneExpr));

+

+      } else if (expr is OldExpr) {

+        var e = (OldExpr)expr;

+        return new OldExpr((e.tok), CloneExpr(e.E));

+

+      } else if (expr is MultiSetFormingExpr) {

+        var e = (MultiSetFormingExpr)expr;

+        return new MultiSetFormingExpr((e.tok), CloneExpr(e.E));

+

+      } else if (expr is FreshExpr) {

+        var e = (FreshExpr)expr;

+        return new FreshExpr((e.tok), CloneExpr(e.E));

+

+      } else if (expr is AllocatedExpr) {

+        var e = (AllocatedExpr)expr;

+        return new AllocatedExpr((e.tok), CloneExpr(e.E));

+

+      } else if (expr is UnaryExpr) {

+        var e = (UnaryExpr)expr;

+        return new UnaryExpr((e.tok), e.Op, CloneExpr(e.E));

+

+      } else if (expr is BinaryExpr) {

+        var e = (BinaryExpr)expr;

+        return new BinaryExpr((e.tok), e.Op, CloneExpr(e.E0), CloneExpr(e.E1));

+

+      } else if (expr is ChainingExpression) {

+        var e = (ChainingExpression)expr;

+        return CloneExpr(e.E);  // just clone the desugaring, since it's already available

+

+      } else if (expr is LetExpr) {

+        var e = (LetExpr)expr;

+        return new LetExpr((e.tok), e.Vars.ConvertAll(CloneBoundVar), e.RHSs.ConvertAll(CloneExpr), CloneExpr(e.Body));

+

+      } else if (expr is ComprehensionExpr) {

+        var e = (ComprehensionExpr)expr;

+        var tk = (e.tok);

+        var bvs = e.BoundVars.ConvertAll(CloneBoundVar);

+        var range = CloneExpr(e.Range);

+        var term = CloneExpr(e.Term);

+        if (e is ForallExpr) {

+          return new ForallExpr(tk, bvs, range, term, null);

+        } else if (e is ExistsExpr) {

+          return new ExistsExpr(tk, bvs, range, term, null);

+        } else if (e is MapComprehension) {

+          return new MapComprehension(tk, bvs, range, term);

+        } else {

+          Contract.Assert(e is SetComprehension);

+          return new SetComprehension(tk, bvs, range, term);

+        }

+

+      } else if (expr is WildcardExpr) {

+        return new WildcardExpr((expr.tok));

+

+      } else if (expr is PredicateExpr) {

+        var e = (PredicateExpr)expr;

+        if (e is AssertExpr) {

+          return new AssertExpr((e.tok), CloneExpr(e.Guard), CloneExpr(e.Body));

+        } else {

+          Contract.Assert(e is AssumeExpr);

+          return new AssumeExpr((e.tok), CloneExpr(e.Guard), CloneExpr(e.Body));

+        }

+

+      } else if (expr is ITEExpr) {

+        var e = (ITEExpr)expr;

+        return new ITEExpr((e.tok), CloneExpr(e.Test), CloneExpr(e.Thn), CloneExpr(e.Els));

+

+      } else if (expr is ParensExpression) {

+        var e = (ParensExpression)expr;

+        return CloneExpr(e.E);  // skip the parentheses in the clone

+

+      } else if (expr is IdentifierSequence) {

+        var e = (IdentifierSequence)expr;

+        var aa = e.Arguments == null ? null : e.Arguments.ConvertAll(CloneExpr);

+        return new IdentifierSequence(e.Tokens.ConvertAll(tk => (tk)), e.OpenParen == null ? null : (e.OpenParen), aa);

+

+      } else if (expr is MatchExpr) {

+        var e = (MatchExpr)expr;

+        return new MatchExpr((e.tok), CloneExpr(e.Source),

+          e.Cases.ConvertAll(c => new MatchCaseExpr((c.tok), c.Id, c.Arguments.ConvertAll(CloneBoundVar), CloneExpr(c.Body))));

+

+      } else {

+        Contract.Assert(false); throw new cce.UnreachableException();  // unexpected expression

+      }

     }

 

+    private bool ResolvePath(ModuleDecl root, List<IToken> Path, out ModuleSignature p) {

+      p = root.Signature;

+      int i = 1;

+      while (i < Path.Count) {

+        ModuleSignature pp;

+        if (p.FindSubmodule(Path[i].val, out pp)) {

+          p = pp;

+          i++;

+        } else {

+          Error(Path[i], "module {0} does not exist", Path[i].val);

+          break;

+        }

+      }

+      return i == Path.Count;

+    }

     public void ResolveTopLevelDecls_Signatures(List<TopLevelDecl/*!*/>/*!*/ declarations, Graph<IndDatatypeDecl/*!*/>/*!*/ datatypeDependencies) {

       Contract.Requires(declarations != null);

       Contract.Requires(datatypeDependencies != null);  // more expensive check: Contract.Requires(cce.NonNullElements(datatypeDependencies));

@@ -419,7 +784,7 @@ namespace Microsoft.Dafny {
           // nothing to do

         } else if (d is ClassDecl) {

           ResolveClassMemberTypes((ClassDecl)d);

-        } else if (d is SubModuleDecl) {

+        } else if (d is ModuleDecl) {

           // TODO: what goes here?

         } else {

           ResolveCtorTypes((DatatypeDecl)d, datatypeDependencies);

@@ -999,23 +1364,15 @@ namespace Microsoft.Dafny {
         } else if (t.ResolvedClass == null) {  // this test is because 'array' is already resolved; TODO: an alternative would be to pre-populate 'classes' with built-in references types like 'array' (and perhaps in the future 'string')

           TopLevelDecl d = null;

           if (t.ModuleName != null) {

-            foreach (var imp in currentClass.Module.Imports) {

-              if (imp.Name == t.ModuleName.val) {

-                // now search among the types declared in module "imp"

-                foreach (var tld in imp.TopLevelDecls) {  // this search is slow, but oh well

-                  if (tld.Name == t.Name) {

-                    // found the class

-                    d = tld;

-                    goto DONE_WITH_QUALIFIED_NAME;

-                  }

-                }

-                Error(t.tok, "Undeclared class name {0} in module {1}", t.Name, t.ModuleName.val);

-                goto DONE_WITH_QUALIFIED_NAME;

+            ModuleDecl m;

+            if (currentClass.Module.Bindings.TryLookup(t.ModuleName, out m)) {

+              if (!m.Signature.TopLevels.TryGetValue(t.Name, out d)) {

+                Error(t.tok, "The name does not exist in the given module");

               }

+            } else {

+              Error(t.ModuleName, "Undeclared module name: {0} (did you forget a module import?)", t.ModuleName.val);

             }

-            Error(t.ModuleName, "Undeclared module name: {0} (did you forget a module import?)", t.ModuleName.val);

-          DONE_WITH_QUALIFIED_NAME: ;

-          } else if (!moduleInfo.Classes.TryGetValue(t.Name, out d)) {

+          } else if (!moduleInfo.TopLevels.TryGetValue(t.Name, out d)) {

             Error(t.tok, "Undeclared top-level type or type parameter: {0} (did you forget a module import?)", t.Name);

           }

 

@@ -2234,13 +2591,14 @@ namespace Microsoft.Dafny {
 

         // Resolution termination check

         if (method.EnclosingClass != null && callee.EnclosingClass != null) {

-          ModuleDecl callerModule = method.EnclosingClass.Module;

-          ModuleDecl calleeModule = callee.EnclosingClass.Module;

+          ModuleDefinition callerModule = method.EnclosingClass.Module;

+          ModuleDefinition calleeModule = callee.EnclosingClass.Module;

           if (callerModule == calleeModule) {

             // intra-module call; this is allowed; add edge in module's call graph

             callerModule.CallGraph.AddEdge(method, callee);

           } else {

-            Contract.Assert(importGraph.Reaches(callerModule, calleeModule));

+            //Contract.Assert(dependencies.Reaches(callerModule, calleeModule));

+            //

           }

         }

       }

@@ -2674,7 +3032,7 @@ namespace Microsoft.Dafny {
       } else if (expr is DatatypeValue) {

         DatatypeValue dtv = (DatatypeValue)expr;

         TopLevelDecl d;

-        if (!moduleInfo.Classes.TryGetValue(dtv.DatatypeName, out d)) {

+        if (!moduleInfo.TopLevels.TryGetValue(dtv.DatatypeName, out d)) {

           Error(expr.tok, "Undeclared datatype: {0}", dtv.DatatypeName);

         } else if (d is AmbiguousTopLevelDecl) {

           Error(expr.tok, "The name {0} ambiguously refers to a type in one of the modules {1}", dtv.DatatypeName, ((AmbiguousTopLevelDecl)d).ModuleNames());

@@ -2952,7 +3310,7 @@ namespace Microsoft.Dafny {
 

           case BinaryExpr.Opcode.Eq:

           case BinaryExpr.Opcode.Neq:

-            if (!CouldPossiblyBeSameType(e.E0.Type, e.E1.Type)) {

+            if (!ComparableTypes(e.E0.Type, e.E1.Type)) {

               if (!UnifyTypes(e.E0.Type, e.E1.Type)) {

                 Error(expr, "arguments must have the same type (got {0} and {1})", e.E0.Type, e.E1.Type);

               }

@@ -3347,6 +3705,31 @@ namespace Microsoft.Dafny {
       }

     }

 

+    private bool ComparableTypes(Type A, Type B) {

+      if (A.IsArrayType && B.IsArrayType) {

+        Type a = UserDefinedType.ArrayElementType(A);

+        Type b = UserDefinedType.ArrayElementType(B);

+        return CouldPossiblyBeSameType(a, b);

+      } else 

+      if (A is UserDefinedType && B is UserDefinedType) {

+        UserDefinedType a = (UserDefinedType)A;

+        UserDefinedType b = (UserDefinedType)B;

+        if (a.ResolvedClass != null && b.ResolvedClass != null && a.ResolvedClass.Name == b.ResolvedClass.Name) {

+          if (a.TypeArgs.Count != b.TypeArgs.Count) {

+            return false; // this probably doesn't happen if the classes are the same.

+          }

+          for (int i = 0; i < a.TypeArgs.Count; i++) {

+            if (!CouldPossiblyBeSameType(a.TypeArgs[i], b.TypeArgs[i]))

+              return false;

+          }

+          // all parameters could be the same

+          return true;

+        }

+        // either we don't know what class it is yet, or the classes mismatch

+        return false;

+      }

+      return false;

+    }

     private bool CouldPossiblyBeSameType(Type A, Type B) {

       if (A.IsTypeParameter || B.IsTypeParameter) {

         return true;

@@ -3541,8 +3924,8 @@ namespace Microsoft.Dafny {
 

         // Resolution termination check

         if (currentFunction != null && currentFunction.EnclosingClass != null && function.EnclosingClass != null) {

-          ModuleDecl callerModule = currentFunction.EnclosingClass.Module;

-          ModuleDecl calleeModule = function.EnclosingClass.Module;

+          ModuleDefinition callerModule = currentFunction.EnclosingClass.Module;

+          ModuleDefinition calleeModule = function.EnclosingClass.Module;

           if (callerModule == calleeModule) {

             // intra-module call; this is allowed; add edge in module's call graph

             callerModule.CallGraph.AddEdge(currentFunction, function);

@@ -3550,7 +3933,7 @@ namespace Microsoft.Dafny {
               currentFunction.IsRecursive = true;  // self recursion (mutual recursion is determined elsewhere)

             }

           } else {

-            Contract.Assert(importGraph.Reaches(callerModule, calleeModule));

+            //Contract.Assert(dependencies.Reaches(callerModule, calleeModule));

           }

         }

       }

@@ -3578,7 +3961,6 @@ namespace Microsoft.Dafny {
       Tuple<DatatypeCtor, bool> pair;

       Dictionary<string, MemberDecl> members;

       MemberDecl member;

-      ModuleDecl module;

       var id = e.Tokens[0];

       if (scope.Find(id.val) != null) {

         // ----- root is a local variable, parameter, or bound variable

@@ -3586,7 +3968,7 @@ namespace Microsoft.Dafny {
         ResolveExpression(r, twoState);

         r = ResolveSuffix(r, e, 1, twoState, allowMethodCall, out call);

 

-      } else if (moduleInfo.Classes.TryGetValue(id.val, out decl)) {

+      } else if (moduleInfo.TopLevels.TryGetValue(id.val, out decl)) {

         if (decl is AmbiguousTopLevelDecl) {

           Error(id, "The name {0} ambiguously refers to a type in one of the modules {1}", id.val, ((AmbiguousTopLevelDecl)decl).ModuleNames());

         } else  if (e.Tokens.Count == 1 && e.Arguments == null) {

@@ -3602,13 +3984,12 @@ namespace Microsoft.Dafny {
           var cd = (ClassDecl)decl;

           r = ResolveSuffix(new StaticReceiverExpr(id, cd), e, 1, twoState, allowMethodCall, out call);

 

-        } else if (decl is SubModuleDecl) {

+        } else if (decl is ModuleDecl) {

           // ----- root is a submodule

-          module = ((SubModuleDecl)decl).SubModule;

           if (!(1 < e.Tokens.Count)) {

-            Error(e.tok, "module {0} is not an expression", module.Name);

+            Error(e.tok, "module {0} cannot be used here", ((ModuleDecl)decl).Name);

           }

-          call = ResolveIdentifierSequenceModuleScope(e, 1, moduleNameInfo[module.Height], twoState, allowMethodCall);

+          call = ResolveIdentifierSequenceModuleScope(e, 1, ((ModuleDecl)decl).Signature, twoState, allowMethodCall);

         } else {

           // ----- root is a datatype

           var dt = (DatatypeDecl)decl;  // otherwise, unexpected TopLevelDecl

@@ -3634,11 +4015,6 @@ namespace Microsoft.Dafny {
           }

         }

 

-      } else if (moduleInfo.ImportedNames.TryGetValue(id.val, out module)) {

-        if (e.Tokens.Count <= 1) {

-          Error(e.tok, "module {0} is not an expression", module.Name);

-        }

-        call = ResolveIdentifierSequenceModuleScope(e, 1, moduleNameInfo[module.Height], twoState, allowMethodCall);

       } else if (classMembers.TryGetValue(currentClass, out members) && members.TryGetValue(id.val, out member)) {

         // ----- field, function, or method

         Expression receiver;

@@ -3671,7 +4047,7 @@ namespace Microsoft.Dafny {
       return call;

     }

 

-    CallRhs ResolveIdentifierSequenceModuleScope(IdentifierSequence e, int p, ModuleNameInformation info, bool twoState, bool allowMethodCall) {

+    CallRhs ResolveIdentifierSequenceModuleScope(IdentifierSequence e, int p, ModuleSignature info, bool twoState, bool allowMethodCall) {

       // Look up "id" as follows:

       //  - unamibugous type/module name (class, datatype, sub-module (including submodules of imports) or arbitrary-type)

       //       (if two imported types have the same name, an error message is produced here)

@@ -3682,9 +4058,8 @@ namespace Microsoft.Dafny {
       CallRhs call = null;

 

       TopLevelDecl decl;

-      ModuleDecl module;

       var id = e.Tokens[p];

-      if (info.Classes.TryGetValue(id.val, out decl)) {

+      if (info.TopLevels.TryGetValue(id.val, out decl)) {

         if (decl is AmbiguousTopLevelDecl) {

           Error(id, "The name {0} ambiguously refers to a something in one of the modules {1}", id.val, ((AmbiguousTopLevelDecl)decl).ModuleNames());

         } else if (decl is ClassDecl) {

@@ -3692,13 +4067,12 @@ namespace Microsoft.Dafny {
           var cd = (ClassDecl)decl;

           r = ResolveSuffix(new StaticReceiverExpr(id, cd), e, p + 1, twoState, allowMethodCall, out call);

 

-        } else if (decl is SubModuleDecl) {

+        } else if (decl is ModuleDecl) {

           // ----- root is a submodule

-          module = ((SubModuleDecl)decl).SubModule;

           if (!(p + 1 < e.Tokens.Count)) {

-            Error(e.tok, "module {0} is not an expression", module.Name);

+            Error(e.tok, "module {0} cannot be used here", ((ModuleDecl)decl).Name);

           }

-          call = ResolveIdentifierSequenceModuleScope(e, p+1, moduleNameInfo[module.Height], twoState, allowMethodCall);

+          call = ResolveIdentifierSequenceModuleScope(e, p + 1, ((ModuleDecl)decl).Signature, twoState, allowMethodCall);

         } else {

           // ----- root is a datatype

           var dt = (DatatypeDecl)decl;  // otherwise, unexpected TopLevelDecl

@@ -4513,7 +4887,7 @@ namespace Microsoft.Dafny {
 

   class CoCallResolution

   {

-    readonly ModuleDecl currentModule;

+    readonly ModuleDefinition currentModule;

     readonly Function currentFunction;

     readonly bool dealsWithCodatatypes;

 

diff --git a/Source/Dafny/Rewriter.cs b/Source/Dafny/Rewriter.cs
index 26ec496e..45e4f50c 100644
--- a/Source/Dafny/Rewriter.cs
+++ b/Source/Dafny/Rewriter.cs
@@ -6,8 +6,8 @@ namespace Microsoft.Dafny
 {

   public interface Rewriter

   {

-    void PreResolve(ModuleDecl m);

-    void PostResolve(ModuleDecl m);

+    void PreResolve(ModuleDefinition m);

+    void PostResolve(ModuleDefinition m);

   }

 

   /// <summary>

@@ -50,7 +50,7 @@ namespace Microsoft.Dafny
   /// </summary>

   public class AutoContractsRewriter : Rewriter

   {

-    public void PreResolve(ModuleDecl m) {

+    public void PreResolve(ModuleDefinition m) {

       foreach (var d in m.TopLevelDecls) {

         bool sayYes = true;

         if (d is ClassDecl && Attributes.ContainsBool(d.Attributes, "autocontracts", ref sayYes) && sayYes) {

@@ -101,7 +101,7 @@ namespace Microsoft.Dafny
       }

     }

 

-    public void PostResolve(ModuleDecl m) {

+    public void PostResolve(ModuleDefinition m) {

       foreach (var d in m.TopLevelDecls) {

         bool sayYes = true;

         if (d is ClassDecl && Attributes.ContainsBool(d.Attributes, "autocontracts", ref sayYes) && sayYes) {

diff --git a/Source/Dafny/Scanner.cs b/Source/Dafny/Scanner.cs
index d35fc22f..307fa321 100644
--- a/Source/Dafny/Scanner.cs
+++ b/Source/Dafny/Scanner.cs
@@ -262,12 +262,12 @@ public class Scanner {
 		start[123] = 10; 

 		start[125] = 11; 

 		start[61] = 57; 

-		start[124] = 58; 

 		start[59] = 19; 

+		start[46] = 58; 

+		start[124] = 59; 

 		start[44] = 20; 

-		start[60] = 59; 

-		start[62] = 60; 

-		start[46] = 61; 

+		start[60] = 60; 

+		start[62] = 61; 

 		start[40] = 22; 

 		start[41] = 23; 

 		start[42] = 24; 

@@ -491,29 +491,29 @@ public class Scanner {
 			case "ghost": t.kind = 8; break;

 			case "module": t.kind = 9; break;

 			case "refines": t.kind = 10; break;

-			case "imports": t.kind = 11; break;

-			case "class": t.kind = 12; break;

-			case "static": t.kind = 13; break;

-			case "datatype": t.kind = 14; break;

-			case "codatatype": t.kind = 15; break;

-			case "var": t.kind = 19; break;

-			case "type": t.kind = 21; break;

-			case "method": t.kind = 24; break;

-			case "constructor": t.kind = 25; break;

-			case "returns": t.kind = 26; break;

-			case "modifies": t.kind = 28; break;

-			case "free": t.kind = 29; break;

-			case "requires": t.kind = 30; break;

-			case "ensures": t.kind = 31; break;

-			case "decreases": t.kind = 32; break;

-			case "bool": t.kind = 35; break;

-			case "nat": t.kind = 36; break;

-			case "int": t.kind = 37; break;

-			case "set": t.kind = 38; break;

-			case "multiset": t.kind = 39; break;

-			case "seq": t.kind = 40; break;

-			case "map": t.kind = 41; break;

-			case "object": t.kind = 42; break;

+			case "as": t.kind = 13; break;

+			case "class": t.kind = 15; break;

+			case "static": t.kind = 16; break;

+			case "datatype": t.kind = 17; break;

+			case "codatatype": t.kind = 18; break;

+			case "var": t.kind = 20; break;

+			case "type": t.kind = 22; break;

+			case "method": t.kind = 25; break;

+			case "constructor": t.kind = 26; break;

+			case "returns": t.kind = 27; break;

+			case "modifies": t.kind = 29; break;

+			case "free": t.kind = 30; break;

+			case "requires": t.kind = 31; break;

+			case "ensures": t.kind = 32; break;

+			case "decreases": t.kind = 33; break;

+			case "bool": t.kind = 36; break;

+			case "nat": t.kind = 37; break;

+			case "int": t.kind = 38; break;

+			case "set": t.kind = 39; break;

+			case "multiset": t.kind = 40; break;

+			case "seq": t.kind = 41; break;

+			case "map": t.kind = 42; break;

+			case "object": t.kind = 43; break;

 			case "function": t.kind = 44; break;

 			case "predicate": t.kind = 45; break;

 			case "reads": t.kind = 46; break;

@@ -648,15 +648,15 @@ public class Scanner {
 				else if (ch >= '0' && ch <= '9') {AddCh(); goto case 18;}

 				else {t.kind = 3; break;}

 			case 19:

-				{t.kind = 18; break;}

+				{t.kind = 12; break;}

 			case 20:

-				{t.kind = 20; break;}

+				{t.kind = 21; break;}

 			case 21:

-				{t.kind = 27; break;}

+				{t.kind = 28; break;}

 			case 22:

-				{t.kind = 33; break;}

-			case 23:

 				{t.kind = 34; break;}

+			case 23:

+				{t.kind = 35; break;}

 			case 24:

 				{t.kind = 47; break;}

 			case 25:

@@ -730,26 +730,26 @@ public class Scanner {
 				else if (ch == ':') {AddCh(); goto case 54;}

 				else {t.kind = 5; break;}

 			case 57:

-				recEnd = pos; recKind = 16;

+				recEnd = pos; recKind = 11;

 				if (ch == '>') {AddCh(); goto case 30;}

 				else if (ch == '=') {AddCh(); goto case 63;}

-				else {t.kind = 16; break;}

+				else {t.kind = 11; break;}

 			case 58:

-				recEnd = pos; recKind = 17;

-				if (ch == '|') {AddCh(); goto case 39;}

-				else {t.kind = 17; break;}

+				recEnd = pos; recKind = 14;

+				if (ch == '.') {AddCh(); goto case 64;}

+				else {t.kind = 14; break;}

 			case 59:

-				recEnd = pos; recKind = 22;

-				if (ch == '=') {AddCh(); goto case 64;}

-				else {t.kind = 22; break;}

+				recEnd = pos; recKind = 19;

+				if (ch == '|') {AddCh(); goto case 39;}

+				else {t.kind = 19; break;}

 			case 60:

 				recEnd = pos; recKind = 23;

-				if (ch == '=') {AddCh(); goto case 41;}

+				if (ch == '=') {AddCh(); goto case 65;}

 				else {t.kind = 23; break;}

 			case 61:

-				recEnd = pos; recKind = 43;

-				if (ch == '.') {AddCh(); goto case 65;}

-				else {t.kind = 43; break;}

+				recEnd = pos; recKind = 24;

+				if (ch == '=') {AddCh(); goto case 41;}

+				else {t.kind = 24; break;}

 			case 62:

 				recEnd = pos; recKind = 83;

 				if (ch == '=') {AddCh(); goto case 42;}

@@ -760,13 +760,13 @@ public class Scanner {
 				if (ch == '>') {AddCh(); goto case 34;}

 				else {t.kind = 77; break;}

 			case 64:

-				recEnd = pos; recKind = 78;

-				if (ch == '=') {AddCh(); goto case 31;}

-				else {t.kind = 78; break;}

-			case 65:

 				recEnd = pos; recKind = 100;

 				if (ch == '.') {AddCh(); goto case 21;}

 				else {t.kind = 100; break;}

+			case 65:

+				recEnd = pos; recKind = 78;

+				if (ch == '=') {AddCh(); goto case 31;}

+				else {t.kind = 78; break;}

 

 		}

 		t.val = new String(tval, 0, tlen);

diff --git a/Source/Dafny/Translator.cs b/Source/Dafny/Translator.cs
index cb154729..7a841a3b 100644
--- a/Source/Dafny/Translator.cs
+++ b/Source/Dafny/Translator.cs
@@ -26,6 +26,7 @@ namespace Microsoft.Dafny {
     readonly Dictionary<TopLevelDecl/*!*/,Bpl.Constant/*!*/>/*!*/ classes = new Dictionary<TopLevelDecl/*!*/,Bpl.Constant/*!*/>();

     readonly Dictionary<Field/*!*/,Bpl.Constant/*!*/>/*!*/ fields = new Dictionary<Field/*!*/,Bpl.Constant/*!*/>();

     readonly Dictionary<Field/*!*/, Bpl.Function/*!*/>/*!*/ fieldFunctions = new Dictionary<Field/*!*/, Bpl.Function/*!*/>();

+    readonly Dictionary<string, Bpl.Constant> fieldConstants = new Dictionary<string,Constant>();

 

     [ContractInvariantMethod]

     void ObjectInvariant()

@@ -52,6 +53,7 @@ namespace Microsoft.Dafny {
       public readonly Bpl.Type HeapType;

       public readonly string HeapVarName;

       public readonly Bpl.Type ClassNameType;

+      public readonly Bpl.Type NameFamilyType;

       public readonly Bpl.Type DatatypeType;

       public readonly Bpl.Type DtCtorId;

       public readonly Bpl.Expr Null;

@@ -70,6 +72,7 @@ namespace Microsoft.Dafny {
         Contract.Invariant(HeapType != null);

         Contract.Invariant(HeapVarName != null);

         Contract.Invariant(ClassNameType != null);

+        Contract.Invariant(NameFamilyType != null);

         Contract.Invariant(DatatypeType != null);

         Contract.Invariant(DtCtorId != null);

         Contract.Invariant(Null != null);

@@ -125,7 +128,7 @@ namespace Microsoft.Dafny {
 

       public PredefinedDecls(Bpl.TypeCtorDecl refType, Bpl.TypeCtorDecl boxType, Bpl.TypeCtorDecl tickType,

                              Bpl.TypeSynonymDecl setTypeCtor, Bpl.TypeSynonymDecl multiSetTypeCtor, Bpl.TypeCtorDecl mapTypeCtor, Bpl.Function arrayLength, Bpl.TypeCtorDecl seqTypeCtor, Bpl.TypeCtorDecl fieldNameType,

-                             Bpl.GlobalVariable heap, Bpl.TypeCtorDecl classNameType,

+                             Bpl.GlobalVariable heap, Bpl.TypeCtorDecl classNameType, Bpl.TypeCtorDecl nameFamilyType,

                              Bpl.TypeCtorDecl datatypeType, Bpl.TypeCtorDecl dtCtorId,

                              Bpl.Constant allocField, Bpl.Constant classDotArray) {

         #region Non-null preconditions on parameters

@@ -157,6 +160,7 @@ namespace Microsoft.Dafny {
         this.HeapType = heap.TypedIdent.Type;

         this.HeapVarName = heap.Name;

         this.ClassNameType = new Bpl.CtorType(Token.NoToken, classNameType, new Bpl.TypeSeq());

+        this.NameFamilyType = new Bpl.CtorType(Token.NoToken, nameFamilyType, new Bpl.TypeSeq());

         this.DatatypeType = new Bpl.CtorType(Token.NoToken, datatypeType, new Bpl.TypeSeq());

         this.DtCtorId = new Bpl.CtorType(Token.NoToken, dtCtorId, new Bpl.TypeSeq());

         this.allocField = allocField;

@@ -179,6 +183,7 @@ namespace Microsoft.Dafny {
       Bpl.TypeCtorDecl seqTypeCtor = null;

       Bpl.TypeCtorDecl fieldNameType = null;

       Bpl.TypeCtorDecl classNameType = null;

+      Bpl.TypeCtorDecl nameFamilyType = null;

       Bpl.TypeCtorDecl datatypeType = null;

       Bpl.TypeCtorDecl dtCtorId = null;

       Bpl.TypeCtorDecl boxType = null;

@@ -202,6 +207,8 @@ namespace Microsoft.Dafny {
             dtCtorId = dt;

           } else if (dt.Name == "ref") {

             refType = dt;

+          } else if (dt.Name == "NameFamily") {

+            nameFamilyType = dt;

           } else if (dt.Name == "BoxType") {

             boxType = dt;

           } else if (dt.Name == "TickType") {

@@ -249,6 +256,8 @@ namespace Microsoft.Dafny {
         Console.WriteLine("Error: Dafny prelude is missing declaration of type Field");

       } else if (classNameType == null) {

         Console.WriteLine("Error: Dafny prelude is missing declaration of type ClassName");

+      } else if (nameFamilyType == null) {

+        Console.WriteLine("Error: Dafny prelude is missing declaration of type NameFamily");

       } else if (datatypeType == null) {

         Console.WriteLine("Error: Dafny prelude is missing declaration of type DatatypeType");

       } else if (dtCtorId == null) {

@@ -267,7 +276,7 @@ namespace Microsoft.Dafny {
         Console.WriteLine("Error: Dafny prelude is missing declaration of class._System.array");

       } else {

         return new PredefinedDecls(refType, boxType, tickType,

-                                   setTypeCtor, multiSetTypeCtor, mapTypeCtor, arrayLength, seqTypeCtor, fieldNameType, heap, classNameType, datatypeType, dtCtorId,

+                                   setTypeCtor, multiSetTypeCtor, mapTypeCtor, arrayLength, seqTypeCtor, fieldNameType, heap, classNameType, nameFamilyType, datatypeType, dtCtorId,

                                    allocField, classDotArray);

       }

       return null;

@@ -325,19 +334,22 @@ namespace Microsoft.Dafny {
           AddClassMembers((ClassDecl)d);

         }

       }

-      foreach (ModuleDecl m in program.Modules) {

+      foreach (ModuleDefinition m in program.Modules) {

         foreach (TopLevelDecl d in m.TopLevelDecls) {

           if (d is ArbitraryTypeDecl) {

             // nothing to do--this is treated just like a type parameter

           } else if (d is DatatypeDecl) {

             AddDatatype((DatatypeDecl)d);

-          } else if (d is SubModuleDecl) {

+          } else if (d is ModuleDecl) {

             // submodules have already been added as a top level module, ignore this.

           } else {

             AddClassMembers((ClassDecl)d);

           }

         }

       }

+      foreach(var c in fieldConstants.Values) {

+        sink.TopLevelDeclarations.Add(c);

+      }

       return sink;

     }

 

@@ -813,7 +825,7 @@ namespace Microsoft.Dafny {
       }

 

       // mh < ModuleContextHeight || (mh == ModuleContextHeight && (fh <= FunctionContextHeight || InMethodContext))

-      ModuleDecl mod = f.EnclosingClass.Module;

+      ModuleDefinition mod = f.EnclosingClass.Module;

       var activateForeign = Bpl.Expr.Lt(Bpl.Expr.Literal(mod.Height), etran.ModuleContextHeight());

       var activateIntra = 

         Bpl.Expr.And(

@@ -1019,7 +1031,7 @@ namespace Microsoft.Dafny {
       return Bpl.Expr.And(lower, upper);

     }

 

-    ModuleDecl currentModule = null;  // the name of the module whose members are currently being translated

+    ModuleDefinition currentModule = null;  // the name of the module whose members are currently being translated

     Method currentMethod = null;  // the method whose implementation is currently being translated

     int loopHeapVarCount = 0;

     int otherTmpVarCount = 0;

@@ -1556,7 +1568,7 @@ namespace Microsoft.Dafny {
       // the procedure itself

       Bpl.RequiresSeq req = new Bpl.RequiresSeq();

       // free requires mh == ModuleContextHeight && fh == FunctionContextHeight;

-      ModuleDecl mod = f.EnclosingClass.Module;

+      ModuleDefinition mod = f.EnclosingClass.Module;

       Bpl.Expr context = Bpl.Expr.And(

         Bpl.Expr.Eq(Bpl.Expr.Literal(mod.Height), etran.ModuleContextHeight()),

         Bpl.Expr.Eq(Bpl.Expr.Literal(mod.CallGraph.GetSCCRepresentativeId(f)), etran.FunctionContextHeight()));

@@ -2374,7 +2386,7 @@ namespace Microsoft.Dafny {
 

           if (options.Decr != null && e.CoCall != FunctionCallExpr.CoCallResolution.Yes) {

             // check that the decreases measure goes down

-            ModuleDecl module = cce.NonNull(e.Function.EnclosingClass).Module;

+            ModuleDefinition module = cce.NonNull(e.Function.EnclosingClass).Module;

             if (module == cce.NonNull(options.Decr.EnclosingClass).Module) {

               if (module.CallGraph.GetSCCRepresentative(e.Function) == module.CallGraph.GetSCCRepresentative(options.Decr)) {

                 bool contextDecrInferred, calleeDecrInferred;

@@ -2792,12 +2804,26 @@ namespace Microsoft.Dafny {
       if (classes.TryGetValue(cl, out cc)) {

         Contract.Assert(cc != null);

       } else {

-        cc = new Bpl.Constant(cl.tok, new Bpl.TypedIdent(cl.tok, "class." + cl.FullCompileName, predef.ClassNameType), true);

+        cc = new Bpl.Constant(cl.tok, new Bpl.TypedIdent(cl.tok, "class." + cl.FullCompileName, predef.ClassNameType), !cl.Module.IsAbstract);

         classes.Add(cl, cc);

       }

       return cc;

     }

 

+    Bpl.Constant GetFieldNameFamily(string n) {

+      Contract.Requires(n != null);

+      Contract.Requires(predef != null);

+      Contract.Ensures(Contract.Result<Bpl.Constant>() != null);

+      Bpl.Constant cc;

+      if (fieldConstants.TryGetValue(n, out cc)) {

+        Contract.Assert(cc != null);

+      } else {

+        cc = new Bpl.Constant(Token.NoToken, new Bpl.TypedIdent(Token.NoToken, "field$" + n, predef.NameFamilyType), true);

+        fieldConstants.Add(n, cc);

+      }

+      return cc;

+    }

+

     Bpl.Expr GetTypeExpr(IToken tok, Type type)

     {

       Contract.Requires(tok != null);

@@ -2857,13 +2883,13 @@ namespace Microsoft.Dafny {
       if (fields.TryGetValue(f, out fc)) {

         Contract.Assert(fc != null);

       } else {

-        // const unique f: Field ty;

+        // const f: Field ty;

         Bpl.Type ty = predef.FieldName(f.tok, TrType(f.Type));

-        fc = new Bpl.Constant(f.tok, new Bpl.TypedIdent(f.tok, f.FullCompileName, ty), true);

+        fc = new Bpl.Constant(f.tok, new Bpl.TypedIdent(f.tok, f.FullCompileName, ty), false);

         fields.Add(f, fc);

-        // axiom FDim(f) == 0 && DeclType(f) == C;

+        // axiom FDim(f) == 0 && FieldOfDecl(C, name) == f;

         Bpl.Expr fdim = Bpl.Expr.Eq(FunctionCall(f.tok, BuiltinFunction.FDim, ty, Bpl.Expr.Ident(fc)), Bpl.Expr.Literal(0));

-        Bpl.Expr declType = Bpl.Expr.Eq(FunctionCall(f.tok, BuiltinFunction.DeclType, ty, Bpl.Expr.Ident(fc)), new Bpl.IdentifierExpr(f.tok, GetClass(cce.NonNull(f.EnclosingClass))));

+        Bpl.Expr declType = Bpl.Expr.Eq(FunctionCall(f.tok, BuiltinFunction.FieldOfDecl, ty, new Bpl.IdentifierExpr(f.tok, GetClass(cce.NonNull(f.EnclosingClass))), new Bpl.IdentifierExpr(f.tok, GetFieldNameFamily(f.Name))), Bpl.Expr.Ident(fc));

         Bpl.Axiom ax = new Bpl.Axiom(f.tok, Bpl.Expr.And(fdim, declType));

         sink.TopLevelDeclarations.Add(ax);

       }

@@ -4387,7 +4413,7 @@ namespace Microsoft.Dafny {
       CheckFrameSubset(tok, method.Mod.Expressions, receiver, substMap, etran, builder, "call may violate context's modifies clause", null);

 

       // Check termination

-      ModuleDecl module = method.EnclosingClass.Module;

+      ModuleDefinition module = method.EnclosingClass.Module;

       if (module == currentModule) {

         if (module.CallGraph.GetSCCRepresentative(method) == module.CallGraph.GetSCCRepresentative(currentMethod)) {

           bool contextDecrInferred, calleeDecrInferred;

@@ -5707,7 +5733,7 @@ namespace Microsoft.Dafny {
           }

           string nm = FunctionName(e.Function, 1 + offsetToUse);

           if (this.applyLimited_CurrentFunction != null && e.Function.IsRecursive) {

-            ModuleDecl module = cce.NonNull(e.Function.EnclosingClass).Module;

+            ModuleDefinition module = cce.NonNull(e.Function.EnclosingClass).Module;

             if (module == cce.NonNull(applyLimited_CurrentFunction.EnclosingClass).Module) {

               if (module.CallGraph.GetSCCRepresentative(e.Function) == module.CallGraph.GetSCCRepresentative(applyLimited_CurrentFunction)) {

                 nm = FunctionName(e.Function, 0 + offsetToUse);

@@ -6525,6 +6551,7 @@ namespace Microsoft.Dafny {
       DtTypeParams, // type parameters of datatype

       TypeTuple,

       DeclType,

+      FieldOfDecl,

       FDim,  // field dimension (0 - named, 1 or more - indexed)

 

       DatatypeCtorId,

@@ -6763,6 +6790,10 @@ namespace Microsoft.Dafny {
           Contract.Assert(args.Length == 1);

           Contract.Assert(typeInstantiation != null);

           return FunctionCall(tok, "DeclType", predef.ClassNameType, args);

+        case BuiltinFunction.FieldOfDecl:

+          Contract.Assert(args.Length == 2);

+          Contract.Assert(typeInstantiation != null);

+          return FunctionCall(tok, "FieldOfDecl", predef.FieldName(tok, typeInstantiation) , args);

         case BuiltinFunction.FDim:

           Contract.Assert(args.Length == 1);

           Contract.Assert(typeInstantiation != null);

diff --git a/Source/Dafny/Util.cs b/Source/Dafny/Util.cs
new file mode 100644
index 00000000..e057727a
--- /dev/null
+++ b/Source/Dafny/Util.cs
@@ -0,0 +1,20 @@
+using System;

+using System.Collections.Generic;

+using System.Linq;

+using System.Text;

+

+namespace Microsoft.Dafny {

+  class Util

+  {

+     public delegate string ToString<T>(T t);

+     public static string Comma<T>(string comma, List<T> l, ToString<T> f) {

+       string res = "";

+       string c = "";

+       foreach(var t in l) {

+         res += c + f(t);

+         c = comma;

+       }

+       return res;

+     }

+  }

+}

diff --git a/Util/VS2010/Dafny/DafnyLanguageService/Grammar.cs b/Util/VS2010/Dafny/DafnyLanguageService/Grammar.cs
index 4244e817..627353bf 100644
--- a/Util/VS2010/Dafny/DafnyLanguageService/Grammar.cs
+++ b/Util/VS2010/Dafny/DafnyLanguageService/Grammar.cs
@@ -19,7 +19,7 @@ namespace Demo
         this.MarkReservedWords(  // NOTE: these keywords must also appear once more below

           "class", "ghost", "static", "var", "method", "constructor", "datatype", "codatatype", "type",

           "assert", "assume", "new", "this", "object", "refines",

-          "module", "imports",

+          "module", "imports", "as",

           "if", "then", "else", "while", "invariant",

           "break", "label", "return", "parallel", "havoc", "print",

           "returns", "requires", "ensures", "modifies", "reads", "decreases",

@@ -277,6 +277,7 @@ namespace Demo
           | "refines"

           | "module"

           | "imports"

+          | "as"

           | "if"

           | "then"

           | "else"