Re: [sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-30 Thread David Joyner
On Sat, Jan 30, 2010 at 7:22 PM, Nicolas M. Thiery nicolas.thi...@u-psud.fr wrote: On Sat, Jan 30, 2010 at 12:59:02AM +0100, Nicolas M. Thiery wrote: Pushed by an example of Sébastien, I just worked a bit further to make matrix groups use categories. In particular:       sage: G = GL(2,GF(3))

Re: [sage-combinat-devel] Re: [sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-29 Thread Sébastien Labbé
Sébastien Labbé: you played quite some with the Cayley graph code. Would you be ok reviewing this part? (unless Robert beats you to it). As a teaser, you might like the following:    sage: M = Monoids().example(); M    An example of a monoid: the free monoid generated by ('a', 'b', 'c', 'd')

[sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-29 Thread javier
Hi Nicolas, On Jan 27, 10:28 pm, Nicolas M. Thiery nicolas.thi...@u-psud.fr wrote:     * Puts all permutation groups and some other finite groups in the       corresponding categories. There remains to handle finite matrix       groups and Galois groups in sage/rings/number_field/.     * As

Re: [sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-29 Thread Nicolas M. Thiery
Dear Javier, Sébastien, Robert, ... On Fri, Jan 29, 2010 at 02:27:25AM -0800, javier wrote: On Jan 27, 10:28 pm, Nicolas M. Thiery nicolas.thi...@u-psud.fr wrote: about #8044: categories for finite/permutation/symmetric groups     * Puts all permutation groups and some other

Re: [sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-29 Thread Nicolas M. Thiery
On Fri, Jan 29, 2010 at 12:44:06PM +0100, Nicolas M. Thiery wrote: Dear David, Javier, Sébastien, Robert, ... On Jan 27, 10:28 pm, Nicolas M. Thiery nicolas.thi...@u-psud.fr By the way, Sébastien, if you want to make a small patch on top of #8044 which would include the cl Cayley

Re: [sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-28 Thread Nicolas M. Thiery
On Wed, Jan 27, 2010 at 08:19:54PM -0800, Chris Godsil wrote: The usual convention in graph theory is that a Cayley graph does _not_ have to be connected. For example it is a basic theorem due to Sabidussi that a graph X is a Cayley graph for a group G if and only if G acts regularly on the

[sage-devel] Re: #8044: Categories for finite/permutation/symmetric groups

2010-01-27 Thread Chris Godsil
The usual convention in graph theory is that a Cayley graph does _not_ have to be connected. For example it is a basic theorem due to Sabidussi that a graph X is a Cayley graph for a group G if and only if G acts regularly on the vertices of X. Since there does not appear to be a significant cost