anchor.diff:      let parseProgramTree (implFile: FSharpImplementationFileContents) =
           match implFile.Declarations with
           | [Entity(Module _, subdecls)] ->
  +            do printfn "%A" subdecls
               visitDeclarations ParsedProgram.empty Set.empty subdecls
           | [_] -> 
               failwith "Top-level declaration can be module only"
  
positive.code:             visitExpression nameOpt predcessors' updatedProgram expr2
              
          | BasicPatterns.Let ((bindVar, bindExpr), bodyExpr) ->
              let updatedProgram, _ = visitExpression (Some bindVar.CompiledName) predcessors parsedProgram bindExpr
              visitExpression nameOpt predcessors updatedProgram bodyExpr
  
          | BasicPatterns.TupleGet (tupleType, index, tupleExpr) ->
              visitCall (None,
                         HiddenOps.TupleGet,
                         HiddenOps.TupleGet,
                         [],
                         Seq.toList tupleType.GenericArguments,
                         [Argument.ofInt index; Expression tupleExpr])
  
negative.code:                     "Functions declaration" |> notSupported
                  else
                      let updatedProgram, _ = 
                          visitExpression (Some funcOrVal.FullName) predcessors program expression
                      visitDeclarations updatedProgram predcessors tail
              
      let (|Module|) (x: FSharpEntity) = if x.IsFSharpModule then Some x else None
  