proposition: Fact refl : reflexive le.
proof: Proof. by move=> [x x']; rewrite /le tagged_asE/= !lexx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)