Added the Subring package

[fragandi]

Hi everyone, here is a small package with methods for handling subrings based on the ones available in SAGBI and in InvariantRing

[d-torrance]

Thanks for the contribution!

In addition to the other comments, there's also a typo:

M2/Macaulay2/packages/Subring/SubringDoc.m2:282: accessable ==> accessible

[d-torrance]

Also, "Subring" should be added to the =distributed-packages file.

[fragandi]

Also, "Subring" should be added to the =distributed-packages file.

I could not find this file, can you give me more details on the path?

[d-torrance]

It's at M2/Macaulay2/packages/=distributed-packages

[fragandi]

Also, "Subring" should be added to the =distributed-packages file.

I could not find this file, can you give me more details on the path?

NWM I thought a file could not start with = but I guess that's ok!

[mahrud]

@fragandi is the plan to eventually make SubalgebraBases depend on this package? Because currently the subring conflict makes them not usable at the same time.

[fragandi]

I have talked to Ollie @ollieclarke8787 before this PR and the idea is indeed to have Subrings as part of the M2 packages and then have SubalgebrasBases call on it. Maybe Ollie you can look into this conflict? Or let me know if I messed up something in the PR.

[mahrud]

The current failure was because you forgot AuxiliaryFiles => true in the package header. The packages are fine alone, just not usable at the same time right now.