baldwin@rochester.ARPA (Douglas Baldwin) (09/23/86)
Thanks to everyone who answered my question a few weeks ago about implementing "for all" in Prolog. The general consensus was that forall X in S, Body can be re-expressed as "there is no X in S such that Body doesn't hold" which can be written in Prolog as not( In_S(X), not Body(X,...) ) (This is a mix of syntaxes from several Prologs, my original description of the problem, etc., but the idea is clear I hope.) This is clearly what I need. Special thanks to Lee Naish, David Morley, Heiner Marxen and Steve Jones for their discussions of this solution.