Singular

Thank you very much for the quick help. I downloaded the new version and now everything works fine! Thanks!

I can't reproduce this crash with Singular 3-1-3-3
[code]
Singular for x86_64-Linux version 3-1-3 (3133- 14431 ) Nov 23 2011 06:13:21
[/code]
Download the recent version from
[code]
http://www.mathematik.uni-kl.de/ftp/pub/Math/Singular/UNIX/nightly_builds/
[/code]
and try again.

If the problem still occurs, then indicate on which machine and with
which operationg system you are working.

Concerning your inqueries the zeroes in the weight vector:

Where did you find:
[quote]Singular's help says that only positive entries are allowed.
[/quote]
The manpage on [b]Global orderings [/b]
http://www.singular.uni-kl.de/Manual/latest/sing_743.htm#SEC795
only says:
[quote][i]Let[/i] w_1,...,w_n are positive integers.[/quote]
As long as Singular does not complain with the definition you make,
it should work in (some sense). The question is whether it is a global ordering.

Dear Singular team,

I try to compute Gröbner bases for the Conti-Traverso procedure, and I need to use a weighted lexicographical ordering (Wp) (in order to obtain a feasible point with minimal costs). Usually, I would just use the cost vector c of my integer linear program. Unfortunately, it contains zero entries (due to the use of slack variables, so this might be a very common problem), and Singular's help says that only positive entries are allowed. However, as I learned from several papers about Conti-Traverso, there should be no problem with working with a weighted lexicographical ordering from arbitrary nonnegative integer vectors in this case. Do you have any suggestions how I could solve or circumvent this problem?
Thanks! Katrin

PS: By the way, Singular produces a seg fault when I use zeros for Wp, and it tells me to inform the authors... :)

> ring R = 0, (w1,w2,w3,t,x1,x2,x3,x4,x5), (lp(4),Wp(1,1,0,0,0));
> poly f1 = w1^2*w2;
Singular : signal 11 (v: 3130/ 14130 ):
current line:>>poly f1 = w1^2*w2;<<
Segment fault/Bus error occurred at 853b33f because of 4 (r:1323172969)
please inform the authors
trying to restart...
o*w2