fact: Definition lift_dlet_prod A B C1 C2 := @lift_dlet A B (C1 * C2).
imports: Coq.ZArith.ZArith Coq.Lists.List Coq.Setoids.Setoid Coq.Classes.Morphisms Coq.QArith.QArith_base Coq.QArith.Qreduction Coq.QArith.Qround