proposition: Lemma conjDg A B x : (A :\: B) :^ x = A :^ x :\: B :^ x.
proof: Proof. by rewrite !setDE !(conjCg, conjIg). Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)