proposition: Lemma mulg_set1 x y : [set x] :* y = [set x * y].
proof: Proof. by rewrite [_ * _]imset2_set1l imset_set1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)