proposition: Lemma mdeg1 i : mdeg U_(i) = 1%N.
proof: Proof. rewrite mdegE (bigD1 i) //= big1 => [|j]; first by rewrite mnmE eqxx addn0. by rewrite mnmE eq_sym => /negbTE ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg