Am Freitag, 19. Juni 2020 18:40:34 UTC+2 schrieb Nils Bruin:
>
> All this disappears once we are happy using functions with two parameters
> as "action operation":
>
> left = G.acting_on_the_left_on(M) # or left = M.left_action_by(G)
>
> left(g,m)
>
> left = G.acting_on_the_right_on(M) # or left
On Friday, June 19, 2020 at 2:24:55 AM UTC-7, Dima Pasechnik wrote:
>
> My problem is that if a group acts on itself, conjugation actions (be
> it h|->ghg^-1 or h|->g^-1 hg)
> are vastly different from regular actions (left or right).
>
> How are you going to use '^' for both?
>
> I think in
On Fri, 19 Jun 2020 at 10:24, Dima Pasechnik wrote:
>
> On Fri, Jun 19, 2020 at 10:14 AM John Cremona wrote:
> >
> > On Fri, 19 Jun 2020 at 09:39, Dima Pasechnik wrote:
> > >
> > >
> > >
> > > On Fri, 19 Jun 2020, 09:05 John Cremona, wrote:
> > >>
> > >> I would like to vote for exponentiation
On Fri, Jun 19, 2020 at 10:14 AM John Cremona wrote:
>
> On Fri, 19 Jun 2020 at 09:39, Dima Pasechnik wrote:
> >
> >
> >
> > On Fri, 19 Jun 2020, 09:05 John Cremona, wrote:
> >>
> >> I would like to vote for exponentiation for a right group action. This is
> >> standard mathematical notation
On Fri, 19 Jun 2020 at 09:39, Dima Pasechnik wrote:
>
>
>
> On Fri, 19 Jun 2020, 09:05 John Cremona, wrote:
>>
>> I would like to vote for exponentiation for a right group action. This is
>> standard mathematical notation (as has already been said), at least in
>> several fields that I know
On Fri, 19 Jun 2020, 09:05 John Cremona, wrote:
> I would like to vote for exponentiation for a right group action. This is
> standard mathematical notation (as has already been said), at least in
> several fields that I know of. Using the shift operators looks too much
> like a
I would like to vote for exponentiation for a right group action. This is
standard mathematical notation (as has already been said), at least in
several fields that I know of. Using the shift operators looks too much
like a computer-sciency solution to me. Sage has always tried to keep its
On 2020-06-18 13:47, Nils Bruin wrote:
>
> To compare: magma has function-application-on-the right in the notation x@f
> and map composition f*g (for right action). So with
Off-topic:
For some programming-language design trivia, the explicit syntax for
function application on the right has a
Am 18.06.2020 um 19:47 schrieb Nils Bruin :
>
> On Thursday, June 18, 2020 at 5:00:00 AM UTC-7, kcrisman wrote:
>
> I assume that would need a pretty major change in the preparser? Does other
> mathematical software use this as a convention? (Just asking, no
> presuppositions here.)
>
>
On Thursday, June 18, 2020 at 5:00:00 AM UTC-7, kcrisman wrote:
>
>
> I assume that would need a pretty major change in the preparser? Does
> other mathematical software use this as a convention? (Just asking, no
> presuppositions here.)
>
No, not the preparser. It would affect the coercion
On Wednesday, June 17, 2020 at 6:01:31 PM UTC-4, Markus Wageringel wrote:
>
> Am Dienstag, 16. Juni 2020 19:03:40 UTC+2 schrieb Nils Bruin:
>>
>> That's quite a thread. One thing I'd like to highlight from there that
>> didn't seem to get so much traction is a point Marco Streng made about
>>
Am Dienstag, 16. Juni 2020 19:03:40 UTC+2 schrieb Nils Bruin:
>
> That's quite a thread. One thing I'd like to highlight from there that
> didn't seem to get so much traction is a point Marco Streng made about
> possible notations for right actions:
>
> If G is a group acting on the right on a
Am Dienstag, 16. Juni 2020 13:40:45 UTC+2 schrieb kcrisman:
>
>
> so, "Permutation" objects aren't really meant to be a group:
>>
>
> I think this is the salient point. Is there any documentation that
> already has matrix(Permutation(...)) ?
>
The documentation of Permutation.to_matrix
On Tue, Jun 16, 2020 at 6:03 PM Nils Bruin wrote:
>
> On Tuesday, June 16, 2020 at 4:40:45 AM UTC-7, kcrisman wrote:
>>
>>
>> For several more points of view (some articulated by people on the current
>> thread), see also the (long) discussion that the ticket you mention led to
>> on this
On Tuesday, June 16, 2020 at 4:40:45 AM UTC-7, kcrisman wrote:
>
>
> For several more points of view (some articulated by people on the current
> thread), see also the (long) discussion that the ticket you mention led to
> on this forum, seven years ago:
>
> so, "Permutation" objects aren't really meant to be a group:
>
I think this is the salient point. Is there any documentation that
already has matrix(Permutation(...)) ?
For several more points of view (some articulated by people on the current
thread), see also the (long) discussion
We also recently had a ticket about correcting the permutation action on a
matrix, so we also need that to also be consistent.
Best,
Travis
On Tuesday, June 16, 2020 at 4:02:11 AM UTC+10, Nils Bruin wrote:
>
> On Monday, June 15, 2020 at 10:43:51 AM UTC-7, Nils Bruin wrote:
>>
>> There's
On Monday, June 15, 2020 at 10:43:51 AM UTC-7, Nils Bruin wrote:
>
> There's obviously the choice for letting permutations/matrices on the
> left/right, but I think there's a definite preferred choice for how to
> convert to a permutation matrix: the one that makes it a homomorphism. And
> for
On Monday, June 15, 2020 at 9:11:08 AM UTC-7, David Joyner wrote:
>
> This is turning into a political discussion:-) I'm not taking sides!
> You can say something similar about left-kernels vs right-kernels of
> matrices, about left-eigenvectors vs right-eigenvectors. Different
> linear algebra
On Mon, Jun 15, 2020 at 11:42 AM 'Paul Mercat' via sage-devel <
sage-devel@googlegroups.com> wrote:
> Thank you for your answers.
>
> It's very confusing to write a right action to the left : we write g(i)
> and not (i)g.
> By default it should be a left action.
>
> And its very confusing that
Group theory convention for composition is the same as in GAP and Magma. It
would be crazy to change it for a variety of reasons...
Whereas Permutation comes from combinatorics, I don't know why they took a
different default.
On Mon, 15 Jun 2020, 16:42 'Paul Mercat' via sage-devel, <
Thank you for your answers.
It's very confusing to write a right action to the left : we write g(i) and
not (i)g.
By default it should be a left action.
And its very confusing that PermutationGroup and Permutation doesn't give
the same matrix for the same permutation.
I think that Sage should
On Mon, Jun 15, 2020 at 11:21 AM 'Paul Mercat' via sage-devel <
sage-devel@googlegroups.com> wrote:
> Another bug with PermutationGroup:
>
> {{
> g1,g2 = PermutationGroup([(1,2,3,4), (1,3,2,4)]).gens()
> (g1*g2)(3), g1(g2(3))
> }}
>
> should gives two times the same result, but it is not the
Another bug with PermutationGroup:
{{
g1,g2 = PermutationGroup([(1,2,3,4), (1,3,2,4)]).gens()
(g1*g2)(3), g1(g2(3))
}}
should gives two times the same result, but it is not the case...
The action of the group on {1,2,3,4} is not an action !
Le lundi 15 juin 2020 16:58:18 UTC+2, Paul Mercat a
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