proposition: Lemma msubsetIl A B : A `&` B `<=` A.
proof: Proof. by apply/msubsetP=> x; rewrite msetE geq_minl. Qed.
imports: mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop tuple) finmap