FACTORIAL

THE BOX'S MAIN HELP:

Returns the factorial of A.
OUT = 1 * 2 * 3 .. A

A (input):

The factorial input value.
This value should be a positive integer.
Values <= 1 yield 1.

OUT (output):

Output is the factorial of the input.
OUT = 1 * 2 * 3 ..on thru the value of 'A'.