class base (x, y) =
	object (self)
		val mutable _x = x
		val mutable _y = y
		method print = print_int (x + y)
	end;;

class derived x =
	let f x = (x + 1, x * 2) in
	object
		inherit base (f x)
	end;;

let a = new derived 1;;
a#print;;