proposition: Fact anti : antisymmetric le.
proof: Proof. by rewrite /le => -[x x'] [y y'] /=; case: comparableP => //= -> /le_anti->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)