assert fun<int:int> is type
assert fun<int:> is type
assert fun<:int> is type
assert fun<int, int: float, str> is type
assert fun< fun<:> : int> is type

let a = fun (x as int, y as int) as int 
	0
end

assert a is fun<int, int: int>
assert !(a is fun<:>)

let b = fun (x as int) as int
	return x * 7
end

assert 42 == b 6

let c = fun () as int
	return 3 * 6
end

assert 18 == *c

let d = fun () as int 
	return 43
	27
end

assert 43 == *d

fun e (n as int) as int
	return n * 2
end

assert 14 == e 7

fun f (n as int) as int
	if n == 0
		return 1
	end

	return n * f(n - 1)
end

assert 120 == f 5