proposition: Lemma subitv_anti : antisymmetric subitv.
proof: Proof. by case=> [? ?][? ?]; rewrite andbACA => /andP[] /le_anti -> /le_anti ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(div fintype bigop order ssralg finset fingroup) mathcomp(ssrnum)