Used for specifying a bound (either upper or lower) as inclusive, exclusive, or unbounded.
interval_contains_exn ~lower ~upper x ~compare raises if lower and upper are crossed.
interval_contains_exn ~lower ~upper x ~compare
lower
upper
compare_to_interval_exn ~lower ~upper x ~compare raises if lower and upper are crossed.
compare_to_interval_exn ~lower ~upper x ~compare