proposition: Fact mul1fx : left_id subfext1 subfext_mul.
proof: Proof. elim/quotW=> x; rewrite !piE /subfx_mul_rep poly_rV_K ?size_poly1 // mul1r. by rewrite modp_small ?rVpolyK // (polySpred nz_p0) ltnS size_poly. 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)