Chaining add function

chain-add.js

/*
  Returns a valuable function:
  x = add(2)(4) // x === 6
  y = x(1)(2) // x === 6 && y === 9
  z = y(10) // z === 19
*/

function add (n) {	
	var fn = function (m) {
		return add(n+m);
	}
	fn.valueOf = function () {
		return n
	}
	return fn
}