proposition: Lemma algC_invautK nu : cancel (algC_invaut nu) nu.
proof: Proof. by move=> x; rewrite /algC_invaut; case: algC_invaut_subproof. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype seq choice) mathcomp(div fintype path bigop finset prime order ssralg) mathcomp(poly polydiv mxpoly generic_quotient countalg) mathcomp(ssrnum closed_field ssrint archimedean rat intdiv) mathcomp(algebraics_fundamentals)