learning_prolog/simple_exercises/fibonacci.pl

fib(N) :-
    write(1),
    write(", "),
    CounterMinusOne is N - 1,
    fib(0, 1, CounterMinusOne).

fib(N1, N2, Counter) :-
    Counter > 0,
    Result is N1 + N2,
    write(Result),
    write(", "),
    CounterMinusOne is Counter - 1,
    fib(N2, Result, CounterMinusOne).