proposition: Lemma lift_mono (M N : {fpmod R}) (psi : 'Mor(M,N)) : is_mono (lift (kernel psi) psi).
proof: Proof. apply/monoP; rewrite /eqmor subr0 /=. rewrite (dvdmx_trans (dvd_col_mxl _ _)) // /lift. by case: eqP (mulkmor psi). 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