type_lt tells whether one type is less than another in the ordering.
FAILURE
Never fails.
EXAMPLE
- type_lt (==`:bool`==) (==`:'a -> 'a`==)
val it = true : bool
COMMENTS
If not (type_lt ty1 ty2) and not (type_lt ty2 ty1), then ty1 = ty2,
although it is faster to directly test for equality. Ordering of types may
be useful in implementing search trees and the like.