On May 18, 8:43 pm, wkehowski <wkehow...@cox.net> wrote: > What about matrix rings over ZZ?
No, but they're not supposed to be. > On May 18, 7:03 pm, John H Palmieri <jhpalmier...@gmail.com> wrote: > > > On May 18, 2:44 pm, benjamin antieau <d.ben.anti...@gmail.com> wrote: > > > > Oh, and this is also the case over other base rings, like over GF(p). > > > > On May 18, 2:43 pm, benjamin antieau <d.ben.anti...@gmail.com> wrote: > > > > > I noticed the following incorrect behavior. > > > > > sage: C=simplicial_complexes.ChessboardComplex(3,3).chain_complex() > > > > sage: C.category() > > > > Category of chain complexes over Integer Ring > > > > sage: A=C.category() > > > > sage: A.is_abelian() > > > > False > > > > > As far as I can tell ChainComplexes inherits is_abelian from > > > > AbelianCategory, so I don't know what the problem is. > > > > > class ChainComplexes(Category_module): > > > > class Category_module(Category_over_base_ring, AbelianCategory): > > > > class AbelianCategory: > > > > def is_abelian(self): > > > > return True > > > The problem is not just chain complexes: > > > sage: RingModules(ZZ).is_abelian() > > False See <http://trac.sagemath.org/sage_trac/ticket/6081> for a patch. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
