Re: Strange ReplaceAll behavior
- To: mathgroup at smc.vnet.net
- Subject: [mg36794] Re: Strange ReplaceAll behavior
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 26 Sep 2002 04:56:46 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <amriq5$53u$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
because te right hand side of SetDelayed[] is not
evaluate.
Try
ru[a] = a -> x;
f[x_] := (a + b) /. ru[a];
f1[x_] := Evaluate[(a + b) /. ru[a]];
and f1[] does what you expect
In[]:={f[c], f1[c]}
Out[]={b + x, b + c}
Regards
Jens
"Lawrence A. Walker Jr." wrote:
>
> Hi,
>
> For the life of me I am not sure why the following is not working in my
> v. 4.2:
>
> ru[a]=a->x;
> f[x_]:=(a+b) /. ru[a];
>
> Why do I get
> f[c] = b+x
>
> and not
> f[c] = b+c?
>
> What gives?
>
> Thanks,
> Lawrence
>
> --
> Lawrence A. Walker Jr.
> http://www.kingshonor.com