fact: Fixpoint remove (i : key) (m : t A) : t A := match m with | Leaf => Leaf | Node l o r => match i with | xH => node l None r | xO ii => node (remove ii l) o r | xI ii => node l o (remove ii r) end end.
imports: Coq(Bool PeanoNat BinPos Orders OrdersEx OrdersLists) MMaps(Utils Comparisons Interface)