proposition: Lemma cr_Product_ones (l: list R): (forall x, In x l -> x [=] [1]) -> cr_Product l [=] [1].
proof: Proof. apply (@cm_Sum_units (Build_multCMonoid R)). Qed.
imports: CoRN.tactics.CornTac CoRN.algebra.CSums CoRN.algebra.CAbMonoids Coq.Sorting.Permutation CoRN.util.SetoidPermutation Coq.Setoids.Setoid Coq.Classes.Morphisms Coq(Lia)