proposition: Lemma mul_rVP m n A B :((@mulmx 1 m n)^~ A =1 mulmx^~ B) <-> (A = B).
proof: Proof. by split=> [eqAB|->//]; apply/row_matrixP => i; rewrite !rowE eqAB. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg countalg finalg zmodp)