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