Dear Forum, as I already replied to the author, the following would work, although I do not know how efficient this is.
gap> a0:=AbelianPcpGroup(3,[0,0,0]); Pcp-group with orders [ 0, 0, 0 ] gap> a:=Subgroup(a0,[a0.1*a0.2^-1,a0.3]); Pcp-group with orders [ 0, 0 ] gap> b:=Subgroup(a0,[a.1*a.2^-1,a.1^-1*a.2^-1]); Pcp-group with orders [ 0, 0 ] gap> a/b; Pcp-group with orders [ 2 ] gap> (here we use multiplicative notation for Abelian groups, which feels odd to me) Best, Dmitrii On 7 March 2010 22:53, Lyosha Beshenov <a...@cadadr.org> wrote: > Hello, > > Here is a typical computational task. > > Given bases of two abelian groups A_1 and A_2, A_2 \subset A_1, > compute the structure of A_1/A_2. > > > For instance, if A_1 has a basis {a - b, c} and A_2 has a basis > {a - b - c, -a + b - c}, then A_1/A_2 is isomorphic to Z/2Z. > > > I'm wondering, is there a straightforward formulation and solution > of this problem in terms of the GAP system? > > > Thank you. > > -- Lyosha > > _______________________________________________ > Forum mailing list > Forum@mail.gap-system.org > http://mail.gap-system.org/mailman/listinfo/forum > -- Dmitrii Pasechnik ----- DISCLAIMER: Any text following this sentence does not constitute a part of this message, and was added automatically during transmission. CONFIDENTIALITY: This email is intended solely for the person(s) named. The contents may be confidential and/or privileged. If you are not the intended recipient, please delete it, notify us, and do not copy or use it, nor disclose its contents. Thank you. Towards A Sustainable Earth: Print Only When Necessary _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum