proposition: Lemma eqmor_mono (phi psi : 'Mor(M, N)) : phi %= psi -> is_mono phi -> is_mono psi.
proof: Proof. move=> eqp phi_mono P kapa. by rewrite -(eqmor_ltrans (eqmorMl _ eqp)) => /phi_mono. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice matrix bigop zmodp mxalgebra poly) ssrcomplements stronglydiscrete coherent edr