anchor.diff:  % and, contains, ends with, in, or, starts with, xor, +, -, *, /, %, ^, [, ..
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
  -fold(FType, Fun, Ctx, _Lvl, {".." = Type, []} = ST) ->
  -    ?debugFmt("wwe debugging fold/5 ===> Start ~p~n ST: ~p~n", [_Lvl, ST]),
  -    NewCtx = case FType of
  -                 top_down -> Fun(ST, Ctx);
  -                 bottom_up -> Ctx
  -             end,
  -    NewCtx1 = case FType of
  -                  top_down -> NewCtx;
  -                  bottom_up -> Fun(ST, NewCtx)
  -              end,
  -    RT = {Type, NewCtx1},
  -    ?debugFmt("wwe debugging fold/5 ===> ~n RT: ~p~n", [RT]),
  -    RT;
  -fold(FType, Fun, Ctx, Lvl, {".." = Type, Value} = ST) ->
  +fold(FType, Fun, Ctx, Lvl, {"[" = Type, {expression, _} = Value} = ST) ->
       ?debugFmt("wwe debugging fold/5 ===> Start ~p~n ST: ~p~n", [Lvl, ST]),
       NewCtx = case FType of
                    top_down -> Fun(ST, Ctx);
  
positive.code:     RT;
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % expression3 .. expression12
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  
negative.code:                   bottom_up -> Fun(ST, NewCtx)
                end,
      RT = {Value, NewCtx1},
      ?debugFmt("wwe debugging fold/5 ===> ~n RT: ~p~n", [RT]),
      RT;
  
  