fact: Definition optrel {A} (R:relation A) : relation (option A) := fun o o' => match o, o' with | Some a, Some a' => R a a' | None, None => True | _,_ => False end.
imports: Coq(Bool Equalities Orders OrdersFacts OrdersLists) Coq(Morphisms Permutation SetoidPermutation) MMaps(Utils Comparisons Interface)