Re: [sage-combinat-devel] multiplicative and additive groups

2013-05-31 Thread Travis Scrimshaw
Hey Mark and Nicolas, > Generally how does one handle the notational difference > > between additive and multiplicative groups? > > I just want to deal with all groups the same way. > > It's a can of worm; as far as I know no system has a good way to > handle this. Probably the easiest for you

Re: [sage-combinat-devel] multiplicative and additive groups

2013-05-31 Thread Nicolas M. Thiery
On Fri, May 31, 2013 at 04:45:13PM -0400, Mark Shimozono wrote: > Anyone understand the behavior > > sage: RR^2 in Groups() > False > > Certainly (RR^2,+) should be a group. Abstractly speaking, yes, RR^2 is a group. But on a computer you need to specify what the notations are for the operations

[sage-combinat-devel] multiplicative and additive groups

2013-05-31 Thread Mark Shimozono
Anyone understand the behavior sage: RR^2 in Groups() False Certainly (RR^2,+) should be a group. I tried to construct GL(2,RR) semidirect RR^2 and found the above behavior. Generally how does one handle the notational difference between additive and multiplicative groups? I just want to deal

Re: [sage-combinat-devel] cristallographic takes two l

2013-05-31 Thread Anne Schilling
Hi Frederic, If you want the English spelling, I think it is "crystallographic". Best, Anne On 5/31/13 12:41 PM, Frédéric Chapoton wrote: > And it is spelled in sage/combinat with just one ! > > I have made a (little bomb) patch at > http://trac.sagemath.org/sage_trac/ticket/14673 > > turnin

Re: [sage-combinat-devel] cristallographic takes two l

2013-05-31 Thread Anne Schilling
Hi Federic, If you want the English spelling, I think it is "crystallographic". Best, Anne On 5/31/13 12:41 PM, Frédéric Chapoton wrote: > And it is spelled in sage/combinat with just one ! > > I have made a (little bomb) patch at > http://trac.sagemath.org/sage_trac/ticket/14673 > > turning

Re: [sage-combinat-devel] On the functorial implmetation of automorphism groups

2013-05-31 Thread Nicolas M. Thiery
On Fri, May 31, 2013 at 03:20:48PM -0400, Mark Shimozono wrote: > Ooh, I can see implementation issues. > They center around evaluating an inverse morphism. Yup, there certainly is no generic way of computing inverse morphisms. Only in certain categories is this guaranteed to be computable / effic

[sage-combinat-devel] cristallographic takes two l

2013-05-31 Thread Frédéric Chapoton
And it is spelled in sage/combinat with just one ! I have made a (little bomb) patch at http://trac.sagemath.org/sage_trac/ticket/14673 turning everything to cristallographic I think this is necessary, but I am afraid it may cause a lot of trouble in the combinat queue Opinions ? Frederic

[sage-combinat-devel] On the functorial implmetation of automorphism groups

2013-05-31 Thread Mark Shimozono
Nicolas, > > Does sage have a functorial Aut construction, > > which yields the group of automorphisms of some object in a category? > > Not yet; it just has End. Ooh, I can see implementation issues. They center around evaluating an inverse morphism. Say f:A--->A is an automorphism of an infin

Re: [sage-combinat-devel] parents with multiple realizations

2013-05-31 Thread Nicolas M. Thiery
On Fri, May 31, 2013 at 01:14:09PM -0400, Mark Shimozono wrote: > Does sage have a functorial Aut construction, > which yields the group of automorphisms of some object in a category? Not yet; it just has End. > I want to use this to define a functorial construction of semidirect products > in t

Re: [sage-combinat-devel] parents with multiple realizations

2013-05-31 Thread Mark Shimozono
Nicolas, Does sage have a functorial Aut construction, which yields the group of automorphisms of some object in a category? I want to use this to define a functorial construction of semidirect products in the Groups() category. Of course it would generally be difficult to test membership in Au