fact: Fixpoint maybeLookup `{Eq a} {b} (v : list (a * b)) (x : a) : Maybe b := match v with | (k, v) :: xs => if k == x then Just v else maybeLookup xs x | _ => Nothing end.
imports: Hask.Ltac Hask.Control.Monad Hask.Data.Eq Hask.Data.Maybe Coq.Program.Wf Coq.Sorting.Sorted Coq.Classes.RelationClasses Coq.Lists.List