Prolog program returns false

Question

I implemented the following power program in Prolog:

puissance(_,0,1).
puissance(X,N,P) :- N>0,A is N-1, puissance(X,A,Z), P is Z*X.

The cod

Answer 1

Can do like this instead:

puissance(X,N,P) :-
  ( N > 0 ->
    A is N-1,
    puissance(X,A,Z),
    P is Z*X
  ; P = 1 ).

Then it will just print one answer.

(Your code leaves a `choice point' at every recursive call, because you have two disjuncts and no cut. Using if-then-else or a cut somewhere removes those. Then it depends on the interpreter what happens. Sicstus still asks if you want ((to try to find)) more answers.)