fac( 0,1 ) :- !.fac( N, Nfac) :-N>0,M is N-1,fac( M, Mfac)Nfac is N * Mfac.
?- fac(5,X)
prog.pl:6:1: syntax error: . or operator expected after expression 1 error(s) compilation failed
Standard output is empty
The brand new service which powers Ideone!
Widget for compiling and running the source code in a web browser!