Max out of values defined by prolog clauses

Question

I know how to iterate over lists in Prolog to find the maximum, but what if each thing is a separate clause? For example if I had a bunch of felines and their ages, how woul

Answer 1

A cat is the oldest if it's a cat and there is not a cat older than it. Let's write that in Prolog:

oldest(X):- cat(X, _), not( thereAreOlders(X)), !.
thereAreOlders(X):- cat(X, N), cat(C, M), C\=X, M > N.

If you consult:

?- oldest(X).
X = sassy.