Edit: Redacted: left for consistency. Had him confused there. A closed form expression is basically just a mathematical function used to model a potentially in

Edit: Redacted: left for consistency. Had him confused there. A closed form expression is basically just a mathematical function used to model a potentially infinite series. Take a look here: http://en.wikipedia.org/wiki/Closed-form_expression http://en.wikipedia.org/wiki/Closed-form_expression Look at the first and second examples. You'll see the big summation sign (for loop: i to infinite) and then an explicit function. If you want to think, what the heck is this math crap used for: think about a more basic everyday concept like recursion. How do you know it will terminate?