Feature suggestion -- return if true

Dave Angel davea at ieee.org
Sun Apr 17 22:04:47 EDT 2011

On 01/-10/-28163 02:59 PM, Chris Angelico wrote:
>  <snip>
> Sure. In my (somewhat contrived) example of factorials, that's going
> to be true (apart from 0! = 0); and if the function returns a string
> or other object rather than an integer, same thing. If there's the

Just to be pedantic, by any reasonable definition, 0! == one, not zero.

One reference:  http://en.wikipedia.org/wiki/Factorial
3rd sentence.

More interestingly, There is a gamma function defined for lots of real 
and complex numbers, which for all non-negative integers matches the 

    gamma(n) = (n-1)!

The gamma function has the same value (1) for one and two, so to be 
consistent, factorial should have that value for both zero and one.


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