Re: Strange ReplaceRepeated
- To: mathgroup at smc.vnet.net
- Subject: [mg17079] Re: Strange ReplaceRepeated
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 17 Apr 1999 03:34:51 -0400
- Organization: Universitaet Leipzig
- References: <7f1dko$kou@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Arturas,
there *is* a '1' in your expression ! Look at
FullForm[Infinity]
In[16]:=
FullForm[Infinity]
Out[16]//FullForm=
DirectedInfinity[1]
you see the '1' ? That must cause a infinite loop, because every time
the DirectedInfinity[1] is found it is replaced by
DirectedInfinity[Infinity] that is DirectedInfinity[DirectedInfinity[1]]
...
Hope that helps
Jens
Arturas Acus wrote:
>
> Dear Group,
>
> Here are very strange rezults from
> RplaceRepeated.
>
> Input:
>
> tarp=List[
> List[AuxVertex[List[List[i2],m2]],
> CG[List[i1,m1],List[i2,m2],List[i3,F[m3]]],
> WD[i1,List[List[m1],List[m2]],List[q0]]],
> List[AuxVertex[List[List[i1],m1]],
> CG[List[i1,m1],List[i2,m2],List[i3,F[m3]]],
> WD[i1,List[List[m1],List[m2]],List[q0]]]]
> Now try this on Linux box:
>
> tarp//.{F[_]:>S[Infinity],_?NumberQ:>S[Infinity]}
>
> It rezults in infinite loop. Using TracePrint indicates, that
> somewhere integer "1" appears for which NumberQ gives True. But there
> isn't '1' at all in tarp! What is happening here?
>
>
> Arturas Acus