val of_int : int -> t
val to_int : t -> int
val to_string : t -> string
returns the string representation. one of: "<", "=", ">"
val neq : t -> bool
val is_eq : t -> bool
val min : ('a -> 'a -> t) -> 'a -> 'a -> 'a
val max : ('a -> 'a -> t) -> 'a -> 'a -> 'a