fact: Fixpoint ins x s := match s with | Leaf => Rd Leaf x Leaf | Node c l y r => match X.compare x y with | Eq => s | Lt => match c with | Red => Rd (ins x l) y r | Black => lbal (ins x l) y r end | Gt => match c with | Red => Rd l y (ins x r) | Black => rbal l y (ins x r) end end end.
imports: Bool List BinPos Pnat Setoid SetoidList PeanoNat