RosettaCodeData/Task/Factorial/Prolog/factorial-2.pro

fact(N, NF) :-
	fact(1, N, 1, NF).

fact(X, X, F, F) :- !.
fact(X, N, FX, F) :-
	X1 is X + 1,
	FX1 is FX * X1,
	fact(X1, N, FX1, F).
A-M baby 2013-04-10 21:29:02 -07:00			`fact(N, NF) :-`
			`fact(1, N, 1, NF).`

			`fact(X, X, F, F) :- !.`
			`fact(X, N, FX, F) :-`
			`X1 is X + 1,`
2016 Update 2016-12-05 22:15:40 +01:00			`FX1 is FX * X1,`
A-M baby 2013-04-10 21:29:02 -07:00			`fact(X1, N, FX1, F).`