(* An Ocaml program *)
(* Inserting an element into a balanced tree *)

type btype = LeftLean | RightLean | Balanced | Leaf
and 'a tree = {key: 'a; tag: btype; left: 'a node; right: 'a node}
and 'a node = Tree of 'a tree | Empty;;

let gulp tr e = match tr with 
   | {key = k; tag = Balanced; left = l; right = r} -> k;;