proposition: Lemma vsval_invf K (w : subvs_of K) : val w^-1 = (vsval w)^-1.
proof: Proof. have [-> | Uv] := eqVneq w 0; first by rewrite !invr0. by apply: vsval_invr; rewrite unitfE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq div) mathcomp(choice fintype tuple finfun bigop ssralg countalg) mathcomp(finalg zmodp matrix vector falgebra poly polydiv) mathcomp(mxpoly generic_quotient)