%% r(_,[go,to,stop],O).

r(X, Input, Output) :-
    'C'(Input, go, Out1),
    'C'(Out1, to, Out2),
    'C'(Out2, stop, Output).

%% p(3,[3],O).

p(X, Input, Output):-
    'C'(Input, X, Output),
    integer(X),
    X > 0.