proposition: Lemma coker_eq0 (phi : 'Epi(M,N)) : coker phi %= 0.
proof: Proof. by case: phi. 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