The subject says it all really. Can anyone justify the following behaviour?
sage: A=AbelianGroup([]) sage: A Trivial Abelian Group sage: A.list() [] sage: list(A) [] sage: A.gens() () sage: B=AbelianGroup([1]) sage: B Multiplicative Abelian Group isomorphic to C1 sage: B.list() [1] sage: list(B) [1] sage: B.gens() (f,) When you create an abelian group by giving a list of generators with their orders, the constructor kills any generators of order 1 UNLESS you give precisely one generator which has order 1: sage: AbelianGroup([1]) Multiplicative Abelian Group isomorphic to C1 sage: AbelianGroup([1,1]) Trivial Abelian Group sage: AbelianGroup([1,1,1]) Trivial Abelian Group Without going so far aw to completely rewrite AbelianGroups -- which really does need doing -- I would propose to stop this quiet deletion of (most) trivial generators. It can only cause confusion: sage: AbelianGroup([2,3,2],names='abc').gens() (a, b, c) sage: AbelianGroup([2,1,2],names='abc').gens() (a, b) In the user's program -- where the orders of the generators will vary at run-time this can only cause trouble. But this is only temporary until someone does a complete rewrite... John --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
