Ticket #13303 (closed defect: fixed)

Opened 10 months ago

Last modified 5 months ago

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 Work issues:
Report Upstream: N/A Reviewers: Travis Scrimshaw
Authors: Xavier Caruso Merged in: sage-5.6.beta0
Dependencies: Stopgaps:

Description (last modified by caruso) (diff)

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 Download

Attachments

trac_13303_invert_polynomial_quotient_rings.patch Download (3.7 KB) - added by caruso 6 months ago.

Change History

comment:1 Changed 10 months ago by caruso

  • Status changed from new to needs_review

comment:2 Changed 10 months ago by caruso

  • Cc caruso added

comment:3 Changed 10 months ago by jdemeyer

Please fill in your real name as Author.

comment:4 Changed 10 months ago by caruso

  • Authors set to Xavier Caruso

comment:5 Changed 8 months ago by burcin

  • Dependencies #13215 deleted

comment:6 Changed 6 months 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 6 months 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 6 months ago by caruso

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

Thanks. I merged your review into my patch.

Changed 6 months ago by caruso

comment:9 Changed 6 months ago by tscrim

For patchbot:

Apply only: trac_13303_invert_polynomial_quotient_rings.patch

comment:10 Changed 5 months ago by jdemeyer

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