Macaulay2 / Macaulay2/M2

unable to adjoin variables to a LocalRing

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Core
Dominant language
Macaulay2
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Forks
297
Avg merge
4d 20h
Merged PRs (30d)
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Description

A LocalRing object is not able to be used as the coefficient ring for a bigger polynomial ring.

Here is some code which reproduces the error:
```m2
needsPackage "LocalRings";
R=ZZ/101[x_1..x_4];
p=ideal(x_1..x_3);
S=R_p;
S[y]
```

And here is the error message:

```m2
stdio:3:1:(3): error: internal error: expected coefficient ring to have a base ring and a flat monoid
```

It would be nice to be able to do this for preserving grading in some cases.

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by running the reported LocalRings example that constructs S = R_p and then evaluates S[y], confirming the coefficient-ring error. Trace the LocalRing and polynomial-ring handling involved in that operation; done means a localized ring can serve as the coefficient ring for a larger polynomial ring while preserving grading as described.

Written by the indexing model from the issue text.

Assessment

Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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