Re: New version, old bugs
- To: mathgroup at smc.vnet.net
- Subject: [mg44127] Re: [mg44093] New version, old bugs
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Thu, 23 Oct 2003 07:16:01 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Wednesday, October 22, 2003, at 04:24 PM, Maxim wrote: > For example: > > In[1]:= > 2*x*y /. x*y -> z > 2*x*y /. s:x*y -> z > > Out[1]= > 2*z > > Out[2]= > 2*x*y > > As I am sure you realize, this problem (like all other pattern matching problem I remember your pointing out), is connected with the Flat attribute (of Times) f[w, f[u, v]] /. s:f[u, v] -> z f[w, z] SetAttributes[f, Flat] f[w, f[u, v]] /. s:f[u, v] -> z f[w, u, v] I have a feeling that there are very few people at WRI who would want to mess with the Flat attribute. I can't say I blame them: the more I think about it the more surprised I am it works as well as it does. Andrzej Kozlowski Yokohama, Japan http://www.mimuw.edu.pl/~akoz/