anchor.diff:      {Scope, Values} =
           lists:foldl(
             fun ({Name, Value}, {VarAcc, ValueAcc}) ->
  -                  NameAst = merl:var(lists:concat(["_Var_", Name, VarScope])),
  +                  NameAst = varname_ast(lists:concat(["_", Name, VarScope])),
                     {[{Name, NameAst}|VarAcc],
                      [?Q("_@NameAst = _@Value")|ValueAcc]
                     }
  
positive.code: 
      NewScope = lists:map(
                   fun ({{identifier, _, LocalVarName}, _Value}) ->
                           {LocalVarName, varify(LocalVarName)}
                   end,
                   ArgList),
  
  
negative.code:     %% setup
      VarScope = lists:map(
                   fun({identifier, {R, C}, Iterator}) ->
                           {Iterator, varname_ast(lists:concat([
                                      Iterator,"/", Level, "_", R, ":", C]))}
                   end, IteratorList),
      {Iterators, IteratorVars} = lists:unzip(VarScope),
  