grammar sacarlambda{

     terminal a,b,c;
     nonterminal S,A,B,C;
     axiom S;

     productions{
          S:=A B b | A B C;
          C:=a b c | A B;
          A:=a A | $;
          B:=b B | $;
     }
}


/*
ENG: We are going to apply the "nullable" algorithm that give us the
     terminals that derivate into the empty string.
ESP: Es una gramatica a la que vamos a aplicar el algoritmo "nullable"
     que nos da los terminales que derivan en la cadena vacia.
*/

print(sacarlambda);
nullable(sacarlambda);