proposition: Fact zeromor_proof : pres N %| pres M *m 0.
proof: Proof. by rewrite mulmx0 dvdmx0. 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