Hi! Maintaining these lookup tables and other tricks is a lot of work, which could be invested elsewhere, e.g. your PHD. Even for me, the difference between these orderings is pure subtility from a users perspective. However the ascending variant is far more efficient with ZDDs.
Michael On 4 Aug., 16:28, Martin Albrecht <[email protected]> wrote: > Hi there, > > in a thread on [sage-support] a bug in our PolyBoRi 0.6 wrapper was discovered > which lead to a wrong GB computation (the result wasn't a Gröbner basis): > > http://is.gd/22e48 > > It turns out this is (partly) due to our trick to implement 'degrevlex', i.e. > we simple put the variables in backward order and maintain a lookup table > which returns the correct index. Of course PolyBoRi doesn't use this lookup > table internally and thus this confuses PolyBoRi's FGLM (it seems) and hence > the wrong result. > > I'd suggest to drop (the broken) support for 'degrevlex' in our PolyBoRi > wrapper and expose dp_asc as 'deglex_asc' instead. > > I could work around this particular issue but it seems this will come back > later in a different form and dropping 'degrevlex' for BooleanPolynomialRing > seems like the right call. > > Thoughts? > Martin > -- > name: Martin Albrecht > _pgp:http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 > _otr: 47F43D1A 5D68C36F 468BAEBA 640E8856 D7951CCF > _www:http://www.informatik.uni-bremen.de/~malb > _jab: [email protected] --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
