fact: Definition merge : t elt -> t elt' -> t elt'' := gmerge (fun k d o => f k (Some d) o) (mapo (fun k d => f k (Some d) None)) (mapo (fun k d' => f k None (Some d'))).
imports: Coq(Bool PeanoNat BinInt FunInd Int) Coq(Orders OrdersFacts OrdersLists) MMaps(Utils Interface OrdList GenTree)