Hi,

This is just a test so I'm not much concerned, but I have these definitions:

type z

type _ s

type (_, _, _) balance =

  | Less : (*∀'a.*) ('a, 'a s, 'a s) balance

  | Same : (*∀'b.*) ('b, 'b, 'b) balance

  | More : (*∀'a.*) ('a s, 'a, 'a s) balance

type _ aVL =

  | Leaf : z aVL