proposition: Lemma dvd1mx m n (M : 'M[R]_(m,n)) : 1%:M %| M.
proof: Proof. by apply/dvdmxP; exists M; rewrite mulmx1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice matrix bigop zmodp mxalgebra poly) ssrcomplements dvdring stronglydiscrete