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Re: Simplify using assumptions and Gamma[*]

• To: mathgroup at smc.vnet.net
• Subject: [mg34763] Re: Simplify using assumptions and Gamma[*]
• From: Peter Pein <petsie at arcor.de>
• Date: Wed, 5 Jun 2002 03:38:23 -0400 (EDT)
• References: <adhru1$3uk$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Michael Chang wrote:
> Hi,
> 
> Since the Euler Gamma function is (n-1)! for n>=1 and n an integer, I
> was wondering why
> 
> FullSimplify[Gamma[n], n>=1 && n \[Element] Integers]
> 
> does not evaluate to (n-1)! ?  Am I missing something here?
> 
> Am I using the Assumptions capability incorrectly?
> 
> Many thanks in advance,
> 
> Michael
> 

Hi Michael,

I'm not sure, but Gamma[n] is a function of one variable, while
(n-1)! is a funtion of the difference of a variable and a constant.
So the latter has a more complicated internal representation, i.e. 
Gamma[n] is simpler.
Simple isn't it? Or am I wrong? Where are the gurus? ;-)

Peter