Question

I got this code that has to run a database as long as N > Order.
My code only runs once :/ ?

display(N) :-
    w(Order,_,Word,Class),
    N > Order -> (write(Word), write(' '), write(Class)),
    nl, fail .

Thanks in advance!

Answer 1

I think you forgot the ‘else’ branch, and the precedence of (->)/2, that’s higher that (,)/2, inhibits the intended order. Try

display(N) :-
    w(Order,_,Word,Class),
    ( N > Order -> write(Word), write(' '), write(Class), nl ; true ),
    fail .