proposition: Lemma rinv_inj (psi : 'Mor(N, M)) : phi ** psi %= idm -> kernel phi %= 0.
proof: Proof. move/(eqmorMl (kernel phi)); rewrite mulmorA mulmor1. by rewrite (eqmor_ltrans (eqmorMr _ (mulkmor _))) mul0mor eqmor_sym. 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