Add GSet methods for blocks and related functions

[mjrodgers]

I have taken a stab at converting the PermGroup blocks method to take a GSet Omega as an argument, but having a little trouble figuring out the last bit.

Ideally we will return a new GSet of blocks that will have the same acting_group as Omega, and the blocks will be subsets of Omega. Currently we have GAP use the permutation action to return the blocks as sets of integers, and generate a GSet from that using on_sets. I'm hoping there is a natural way to compose on_sets with action_function(Omega), any thoughts on this? (Once this is working I will copy the approach for the other relevant functions).

[mjrodgers]

@fingolfin I added some rough implementations of the other methods, I will keep working to add documentation.

Is the return for maximal_blocks for PermGroup supposed to use on_sets? It seems like it should.

[fingolfin]

I'm hoping there is a natural way to compose on_sets with action_function(Omega), any thoughts on this?

Hmm, good question, I am not sure. I mean of course if action_function(Omega) is on_points resp. ^ then then the "composition" is clear, but what if one starts with something custom? Hmm

In general of course the action can also be nested; e.g. the action on a block system may itself admit non-trivial blocks, which then would be sets-of-sets-of-something (with "something" the initial objects, e.g. integers).

I need to think about this, and perhaps we need to discuss it in person next week.

I added some rough implementations of the other methods, I will keep working to add documentation.

Thank you!

Is the return for maximal_blocks for PermGroup supposed to use on_sets? It seems like it should.

This sounds plausible.

[fingolfin]

@mjrodgers this is still marked as draft, is there anything missing or is it "ready for review" (if so please press that button :-) )

[mjrodgers]

@fingolfin I will finish up the tests tomorrow morning and move it to review hopefully before triage :)

…

On 18. Mar 2025, at 6:17 PM, Max Horn ***@***.***> wrote: fingolfin left a comment (oscar-system/Oscar.jl#4692) @mjrodgers this is still marked as draft, is there anything missing or is it "ready for review" (if so please press that button :-) ) — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you were mentioned. <https://github.com/mjrodgers> <#4692 (comment)> <https://github.com/notifications/unsubscribe-auth/AANWIWIPS26X5PEZBWBFW5T2VBIJ7AVCNFSM6AAAAABYJTAG2GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMZUGA4TONRQGA> fingolfin left a comment (oscar-system/Oscar.jl#4692) <#4692 (comment)> @mjrodgers <https://github.com/mjrodgers> this is still marked as draft, is there anything missing or is it "ready for review" (if so please press that button :-) ) — Reply to this email directly, view it on GitHub <#4692 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AANWIWIPS26X5PEZBWBFW5T2VBIJ7AVCNFSM6AAAAABYJTAG2GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMZUGA4TONRQGA>. You are receiving this because you were mentioned.