proposition: Fact mulfx_addl : left_distributive subfext_mul subfext_add.
proof: Proof. elim/quotW=> x; elim/quotW=> y; elim/quotW=> w. by rewrite !piE /subfx_mul_rep linearD /= mulrDl modpD linearD. 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)