On Mon, Dec 9, 2024 at 8:45 PM Mikael Djurfeldt <mik...@djurfeldt.com> wrote:
> On Mon, Dec 9, 2024 at 8:23 PM <to...@tuxteam.de> wrote: > >> (lambda (p1 p2) (< (car p1) (car p2))) >> >> Then you'd need a corresponding equal, because otherwise you >> end up with things which are neither less nor equal nor greater, >> i.e. the ordering isn't total, which is bad for sorting :) >> > > `sort' assumes that the elements belong to a "strict total order", which > means that the connectedness-axiom is true, which means that a = b is > *equivalent to* not (a < b or a > b). So, we don't need equal. > Actually, a "total order" is sufficient for `sort', because equal is not necessary for sorting. I should have said that if we have a "strict total order" (as is almost always the case) is sufficient for the equivalence I have been talking about.
