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Re: Pattern matches only when named

• To: mathgroup at smc.vnet.net
• Subject: [mg43885] Re: [mg43873] Pattern matches only when named
• From: "Peter Pein" <petsie at arcor.de>
• Date: Fri, 10 Oct 2003 03:05:53 -0400 (EDT)
• References: <200310090555.BAA06789@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

in general f != g

Peter Pein, Berlin
petsie at arcAND.de
replace && by || to write to me


----- Original Message ----- 
From: "Ken Morgan" <kemorgan at vt.edu>
To: mathgroup at smc.vnet.net
Subject: [mg43885] [mg43873] Pattern matches only when named


> Just a curiosity:
> 
> In[1]:=   f + g /. u_ + _ -> h
> Out[1]:=  h
> 
> but
> 
> In[2]:=   f + g /. _ + _ -> h
> Out[2]:=  f + g
> 
> Why does the pattern match only when one of the Blanks has a name?
> 
> 
> Thanks,
> Ken
> 

• References:
  • Pattern matches only when named
    • From: Ken Morgan <kemorgan@vt.edu>