proposition: Lemma lker0_lfunK f : lker f == 0%VS -> cancel f f^-1%VF.
proof: Proof. by move/lker0P=> injf u; apply: injf; rewrite limg_lfunVK ?memv_img ?memvf. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)