Re: Bug in ReplaceAll and ReplaceRepeated?
- To: mathgroup at smc.vnet.net
- Subject: [mg44028] Re: Bug in ReplaceAll and ReplaceRepeated?
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 18 Oct 2003 03:12:21 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <bmoe32$htd$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
have you ever considered to read the manual ?
"A list of rules can be given. The rules are tried in order.
The result of the first one that applies is returned. ..."
The (a_ + b_)^c_ :> Expand[(a + b)^c] matches first because
the pattern matcher works from outer to inner expressions,
and so the Z->2 rule is never applied, because the second rule
matches always first.
Regards
Jens
Artþras Acus wrote:
>
> Hi,
>
> Sqrt[(X + Y + Z)^2] //. {Z -> 2, (a_ + b_)^c_ :> Expand[(a + b)^c]}
>
> don't replace Z with 2. If I remove c in right hand side of second rule,
> works as expected.
>
> is the following behaviour bug or the feature?
> In applies both to 4.1, and 5.0.