automaton auto1{

     states q0,q1,q2,q3;
     alphabet a,b;
     initial q0;
     final q3;

     transition{

          q0,a=q1;
          q0,b=q2;

          q1,a=q1;
          q1,b=q3;

          q2,a=q0;
          q2,b=q2;

          q3,a=q3;
          q3,b=q2;
     }
}

regexp exp1{ (a*)bbb(a*) }

pdautomaton apila{
     states q0,q1;
     alphabet a,b;
     stack A,B,Z0;
     initial q0;
     stackinitial Z0;
     transition{
          q0,a,(Z0)=q0,(A,Z0);
          q0,a,(A)=q0,(A,A);
          q0,b,(A)=q1,($);
          q1,b,(A)=q1,($);
          q1,$,(Z0)=q1,($);
     }
}

/*
ENG: First we print the automatons and the regular expression.
ESP: Primero imprimimos los automatas y la expresion regular.
*/

print(apila);
print(auto1);
print(exp1);


/*
ENG: Now we will see if the automatons and the regular expression
     recognize the string [a b b a b b a a b a a b a a b a].
ESP: Ahora veremos si los automatas y la expresion regular
     reconocen la cadena [a b b a b b a a b a a b a a b a].
*/

recognize(auto1,a b b a b b a a b a a b a a b a);
recognize(exp1,a b b a b b a a b a a b a a b a);
recognize(apila,a b b a b b a a b a a b a a b a);