objeto :- write('{'),aux1, write('}').

atributo :-cadena, write(':'),valor,aux2.
arreglo :- write('['),aux3, write(']').
aux1 :- read(X),(X='atributo'->atributo;
                 X='fin'->write('')).
aux2 :- read(X),(X='atributo'->write(','),atributo;
                 X='fin'->write('')).
aux3 :- read(X),(X='valor'->valor,aux4;
                 X='fin'->write('')).
aux4 :- read(X),(X='valor'->write(','),valor,aux4;
                 X='fin'->write('')).
cadena :- read(X),write('"'),write(X),write('"').
numero :- read(X),write(X).
valor :-read(T),(T='cadena'->cadena;
                 T='numero'->numero;
                 T='arreglo'->arreglo;
                 T='objeto'->objeto).
:- objeto.