#20214: Type inconsistencies in polynomial factorization
-------------------------------------+-------------------------------------
Reporter: vdelecroix | Owner:
Type: defect | Status: needs_work
Priority: major | Milestone: sage-7.1
Component: algebra | Resolution:
Keywords: | Merged in:
Authors: Benjamin Hackl | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/behackl/polynomial/unit-parent- | e7d04c28ada863dd70b254707848bb57d3e65a35
inconsistent | Stopgaps:
Dependencies: |
-------------------------------------+-------------------------------------
Comment (by mmarco):
My two cents: factoring makes sense in rings (more precisely, in UFD's),
so the factors and the unit should be in the corresponding ring.
So, I think that the correct behaviour should be the opposite of what you
propose. That is, we should have:
{{{
sage: R.<x> = ZZ[]
sage: parent((x+1).factor().unit())
Univariate Polynomial Ring in x over Integer Ring
sage: parent(R.one().factor().unit())
Univariate Polynomial Ring in x over Integer Ring
}}}
There might be rings (e.g. Laurent polynomials) with units that are not in
the rings base ring. So the only possible consistent behaviour is to have
the units in the ring (and not in its base ring).
--
Ticket URL: <http://trac.sagemath.org/ticket/20214#comment:12>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
