Dear Lev Glebsky,
Thank you very much for this bug report. It was prompted by a misprint in a book and will be fixed in the next release of GAP. Regards, Alexander Hulpke On Apr 8, 2013, at 4/8/13 12:11, gleb...@cactus.iico.uaslp.mx wrote: > Well.. It is known that the groups > M(a,b,c)=<x,y,z | x^y=x^a, y^z=y^b, z^x=z^b> are finite (see for example > D.L. Johnson Presentations of groups, Ch.7, exercise 16). > (Here a,b,c are natural numbers, x^y=y^(-1)*x*y.) > > But running > GAP (inside SAGE) I have got: > > sage: f:=FreeGroup("a","b","c"); > sage: > G:=f/[f.2^-1*f.1*f.2*f.1^-4,f.3^-1*f.2*f.3*f.2^-4,f.1^-1*f.3*f.1*f.3^-4]; > <free group on the generators [ a, b, c ]> > <fp group on the generators [ a, b, c ]> > sage: AbelianInvariants(G); > [ 3, 3, 3 ] > sage: NewmanInfinityCriterion(G,3) > true > > Looks wrong? As far as I understand, passing NewmanInfinityCriterion(G,3) > meens that G has arbitrary large homomorphic images in 3-groups. It seems > to contradict with the following (G is the same as above): > > sage: G3:=PQuotient(G,3); > sage: h3:=EpimorphismQuotientSystem(G3); > <3-quotient system of 3-class 4 with 9 generators> > [ a, b, c ] -> [ a1, a2, a3 ] > sage: G3:=Image(h3) > <pc group of size 19683 with 9 generators> > > I am new user of the GAP. I starting to play with a GAP inside SAGE, 4.4.2, > > Lev. > > _______________________________________________ > 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