Nope, in vanilla Prolog you'd have to type "
X(A,C) :-
X(A,B),
X(B,C)." for every single
X you want to be transitive.
In formal logic, "A if B" is just syntactic sugar for "(B && A) || (!B)" or in English: when B is true, A is true. (But when B is false, A could be either true or false.) So you could rewrite your expression as (edit: fixed):
transitive(X, A, B, C) :- (X(A,B), X(B,C), X(A,C)); not(X(A,B), X(B,C)).
In formal logic, "A if B" is just syntactic sugar for "(B && A) || (!B)" or in English: when B is true, A is true. (But when B is false, A could be either true or false.) So you could rewrite your expression as (edit: fixed):