type t =
| Var of Identifier.t
| Int
| Product of t * t
| Arrow of t * t
[@@deriving eq, ord, show]
let rec string_of_type = function
| Var v -> "Var '" ^ v ^ "'"
| Int -> "Int"
| Product (a, b) -> "Product(" ^ string_of_type a ^ ", " ^ string_of_type b ^ ")"
| Arrow (a, b) -> "Arrow(" ^ string_of_type a ^ ", " ^ string_of_type b ^ ")"
;;
