proposition: Fact mulVf u : u != 0 -> inv u * u = 1.
proof: Proof. rewrite -(inj_eq CtoL_inj) rmorph0 => nz_u. by apply: CtoL_inj; rewrite !LtoC_K mulVf. 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)