proposition: Lemma eval_mulmx e m n p (A : 'M[term]_(m, n)) (B : 'M_(n, p)) : eval_mx e (mulmx_term A B) = eval_mx e A *m eval_mx e B.
proof: Proof. apply/matrixP=> i k; rewrite !mxE /= ((big_morph (eval e)) 0 +%R) //=. by apply: eq_bigr => j _; rewrite /= !mxE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(div fintype tuple finfun bigop fingroup perm) mathcomp(ssralg zmodp matrix mxalgebra poly polydiv)