proposition: Lemma cokerK (M N : {fpmod R}) (phi : 'Mor(M,N)) : coker (coker phi) %= 0.
proof: Proof. by rewrite /eqmor subr0 dvd_col_mxl. 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