Opened 9 years ago

Last modified 8 years ago

#13184 closed defect

Some Homset are not unique parents — at Version 6

Reported by: caruso Owned by: nthiery
Priority: major Milestone: sage-5.10
Component: categories Keywords: homset unique parent
Cc: caruso, SimonKing, nbruin Merged in:
Authors: Xavier Caruso Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by saraedum)

I guess it is a bug:

sage: k = GF(5) 
sage: H = Hom(k,k)
sage: H2 = Hom(k,k)
sage: H is H2

I don't know what is the correct way to fix this problem.

More precisely, in sage.categories.homset (l. 223-227), one can read:

    # Apparently X._Hom_ is supposed to be cached
    return X._Hom_(Y, category)
except (AttributeError, TypeError):

However, in this particular case, k._Hom_ is apparently not cached. IMHO, caching should be the job of sage.categories.homset.Hom is all cases, but I might be wrong.


  1. trac_13184.patch

to the sage library.

Change History (8)

Changed 9 years ago by caruso

comment:1 Changed 9 years ago by caruso

I've attached a small patch fixing the problem.

comment:2 Changed 9 years ago by caruso

  • Status changed from new to needs_review

comment:3 Changed 9 years ago by caruso

  • Cc caruso added

comment:4 Changed 9 years ago by jdemeyer

Please fill in your real name as Author.

comment:5 Changed 9 years ago by caruso

  • Authors set to Xavier Caruso

Changed 8 years ago by saraedum

added .patch to the existing patch so the patchbot picks it up

comment:6 Changed 8 years ago by saraedum

  • Description modified (diff)
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