]> skaller writes: Subject: Re: [Caml-list] Weird behavior with nan's and min/max The idea that x = x isn't universally true is mathemtically absurd. I don't think it has to do with mathematics. It has to do with logic. While there is only one mathematic, there lots of logics around. Some of those are totally sensible, still they do not let you deduce x = x for all x. The prominent examples are logics that deal with undefined terms and partial functions. In this field a popular approach is to use existential equality: x = y is true iff both are defined and equal. The advantage of this approach is that you don't need an additional definedness predicate and (more importantly) the equality relation is recursively enumerable (if you don't mess things up in the rest of the logic). In this light, I think it might be absurd to have x = x universally true, because sometimes you can't even tell if x = x (because there is no algorithm that can decide it). ;-) (However, most of the time I use higher-order logics in which x = x is always true.) Bye, Hendrik Tews ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners