proposition: Lemma scalerKV a : a != 0 -> cancel ( *:%R a^-1 : V -> V) ( *:%R a).
proof: Proof. by rewrite -invr_eq0 -{3}[a]invrK; apply: scalerK. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)