Dear Forum,
> On Jan 21, 2015, at 1/21/15 6:32, Ali <alireza_abdoll...@yahoo.com> wrote: > > Dears, > > I have a long list L of groups with finite presentations. I would like to > apply IsAbelian on L and Filtered all groups which are not Abelian. Through > the computations, IsAbelian could not treat an special group and so the > Filtered will not be terminated. I would like to know if there is a way to > define a third output for IsAbelian such as FAIL which means that it is tried > to test abelianness by a certain limit ( e.g. Time or number of cosets or > ...) but not succeeded. If such thing exists I can apply this new IsAbelian > to the list L to obtain all groups which are not abelian or the old IsAbelian > fails to give a true or false. Then I can handle the filtered list by hand > since I guess the latter list should be short. > > The same question for IsSolvable and .... This depends a bit on the groups in question, but `IsAbelian' etc. will by default calculate a faithful representation. If your groups are huge this will most likely fail every time. What I would do as a first step is to look at quotient groups: Solvable Quotient, Action on cosets of Low Index subgroups and see whether rthese quotient groups already exclude the properties. This has (quotient size/subgroup index) easy parameters that will limit the initial calculations. This should give you a good initial filtering of non-candidates. Best, Alexander Hulpke > > Best Wishes > Alireza Abdollahi > _______________________________________________ > Forum mailing list > Forum@mail.gap-system.org > http://mail.gap-system.org/mailman/listinfo/forum _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
