Opened 9 years ago

Closed 9 years ago

#13303 closed defect (fixed)

is_unit and __invert__ for Polynomial Quotient Rings

Reported by: caruso Owned by: AlexGhitza
Priority: major Milestone: sage-5.6
Component: algebra Keywords: inversion quotient polynomial rings
Cc: caruso Merged in: sage-5.6.beta0
Authors: Xavier Caruso Reviewers: Travis Scrimshaw
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by caruso)

As it was noticed in ticket #13215, inversion in Polynomial Quotient Rings does not work quite well:

sage: Z16x.<x> = Integers(16)[]
sage: GR.<y> =  Z16x.quotient(x^2 + x + 1)
sage: (2*y)^(-1)
15*y + 15
sage: (2*y)*(2*y)^(-1)
2

I attach a small patch "fixing" this problem: with the patch, a NotImplemetedError? is raised when the base ring is not a field.

Apply trac_13303_invert_polynomial_quotient_rings.patch

Attachments (1)

trac_13303_invert_polynomial_quotient_rings.patch (3.7 KB) - added by caruso 9 years ago.

Download all attachments as: .zip

Change History (11)

comment:1 Changed 9 years ago by caruso

  • Status changed from new to needs_review

comment:2 Changed 9 years ago by caruso

  • Cc caruso added

comment:3 Changed 9 years ago by jdemeyer

Please fill in your real name as Author.

comment:4 Changed 9 years ago by caruso

  • Authors set to Xavier Caruso

comment:5 Changed 9 years ago by burcin

  • Dependencies #13215 deleted

comment:6 Changed 9 years ago by tscrim

  • Reviewers set to Travis Scrimshaw

I've uploaded a review patch which corrects a few documentation issues. If you agree, you can set this to a positive review. Thanks.

comment:7 Changed 9 years ago by tscrim

Added a proper commit message to review patch. The trailing whitespace is taken care of in there as well.

comment:8 Changed 9 years ago by caruso

  • Description modified (diff)
  • Status changed from needs_review to positive_review

Thanks. I merged your review into my patch.

comment:9 Changed 9 years ago by tscrim

For patchbot:

Apply only: trac_13303_invert_polynomial_quotient_rings.patch

comment:10 Changed 9 years ago by jdemeyer

  • Merged in set to sage-5.6.beta0
  • Resolution set to fixed
  • Status changed from positive_review to closed
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