duchier@cs.yale.edu (Denys Duchier) (12/13/90)
In article <5398@rex.cs.tulane.edu> feldman@rex.cs.tulane.edu (Damon Feldman) writes: > I was writing a small prolog program, and I had use for the following > predicate: > > notequal(X,Y) :- nonvar(X),nonvar(Y),X=Y,!,fail. > notequal(X,_) :- var(X),!,fail. > notequal(_,Y) :- var(Y),!,fail. > notequal(_,_). Why not just: notequal(X,Y) :- nonvar(X),nonvar(Y),X\=Y. --Denys