module Fun:sig..end
Function values.
val id : 'a -> 'aid is the identity function. For any argument x, id x is x.
val const : 'a -> 'b -> 'aconst c is a function that always returns the value c. For any
argument x, (const c) x is c.
val flip : ('a -> 'b -> 'c) -> 'b -> 'a -> 'cflip f reverses the argument order of the binary function
f. For any arguments x and y, (flip f) x y is f y x.
val negate : ('a -> bool) -> 'a -> boolnegate p is the negation of the predicate function p. For any
argument x, (negate p) x is not (p x).