test.ml

type binop = Add | Sub | Mul | Div
type cmpop = Lt | Gt | LtEq | GtEq | Eq | NotEq

type 'a arith = AInt : int arith | AFloat : float arith
type 'a comparable =
  | CBool : bool comparable
  | Arith : 'a arith -> 'a comparable

type 'a expr =
  | Bool : bool -> bool expr
  | Int : int -> int expr
  | Float : float -> float expr
  | BinOp : 'a arith * binop * 'a expr * 'a expr -> 'a expr
  | Cmp : 'a comparable * cmpop * 'a expr * 'a expr -> bool expr
  | Not : bool expr -> bool expr
  | And : bool expr * bool expr -> bool expr
  | Or : bool expr * bool expr -> bool expr