On Thu, Apr 4, 2024 at 11:07 AM Dima Pasechnik <dimp...@gmail.com> wrote: > > Yes, it's surely a bug; this example gives |gg|=2^27 (wow!), or a smaller one: > > sage: g=AbelianGroup([2,2]) > sage: gg=g.subgroup(g.list()) > sage: gg.cardinality().factor() # what? > 2^3 > sage: g.cardinality().factor() > 2^2 > > Maybe related to https://github.com/sagemath/sage/pull/36986 ?
yes, indeed, it came from https://github.com/sagemath/sage/pull/36986 I've opened https://github.com/sagemath/sage/issues/37744 > > On Thu, Apr 4, 2024 at 10:24 AM 'B. L.' via sage-devel > <sage-devel@googlegroups.com> wrote: > > > > Hello, > > to me it seems that with 10.3 there might be a bug in ".subgroup", see > > example below. The subgroup cardinality is wrong and the equality test of > > the group and the subgroup generated by all group elements yields "False". > > In previous versionls of SAGE this worked as expected. > > Can anybody help? > > Thanks and kind regards, > > Barbara > > > > > > sage: g = AbelianGroup([4, 4]) > > sage: gg = g.subgroup(g.list()) > > sage: g > > Multiplicative Abelian group isomorphic to C4 x C4 > > sage: gg > > Multiplicative Abelian subgroup isomorphic to C4 x C4 generated by {f1, > > f1^2, f1^3, f0, f0*f1, f0*f1^2, f0*f1^3, f0^2, f0^2*f1, f0^2*f1^2, > > f0^2*f1^3, f0^3, f0^3*f1, f0^3*f1^2, f0^3*f1^3} > > sage: g.cardinality() > > 16 > > sage: gg.cardinality() > > 134217728 > > sage: g==gg > > False > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sage-devel" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to sage-devel+unsubscr...@googlegroups.com. > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/sage-devel/55ecbb00-3927-4339-8cb3-f68347358446n%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/CAAWYfq17xtj%2BroU9QWBMF6DV4HmPRg4EmgpXnLRzsad%2BZ8k6MA%40mail.gmail.com.
