anchor.diff:  
       NewScope = lists:map(
                    fun ({{identifier, _, LocalVarName}, _Value}) ->
  -                         {LocalVarName, varify(LocalVarName)}
  +                         {LocalVarName, varname_ast(LocalVarName)}
                    end,
                    ArgList),
   
  
positive.code:     {Scope, Values} =
          lists:foldl(
            fun ({Name, Value}, {VarAcc, ValueAcc}) ->
                    NameAst = merl:var(lists:concat(["_Var_", Name, VarScope])),
                    {[{Name, NameAst}|VarAcc],
                     [?Q("_@NameAst = _@Value")|ValueAcc]
                    }
  
negative.code: 
  scope_as(VarName, Contents, TreeWalker) ->
      {{ContentsAst, ContentsInfo}, TreeWalker1} = body_ast(Contents, TreeWalker),
      VarAst = varname_ast(VarName),
      {Id, TreeWalker2} = begin_scope(
                            {[{VarName, VarAst}],
                             [?Q("_@VarAst = _@ContentsAst")]},
  