Quotients of polynomials rings over boolean rings

[nbruin]

We have a problem in 8.4 that didn't arise in 8.2:

sage: R.<a0,a1,a2>=BooleanPolynomialRing()
sage: P.<X>=R[]
sage: PQ.<t>=P.quo(X^4+X+1)
sage: (t^4+t+1)==0 #problem
False
sage: (t^4+t+1).is_zero() #correct
True

See https://groups.google.com/d/msg/sage-devel/JuxpFfaKYzA/wdfobJ3GCAAJ

CC: @saraedum @xcaruso @roed314

Component: algebra

Author: Martin Rubey

Branch/Commit: u/mantepse/quotients_of_polynomials_rings_over_boolean_rings @ 8bfb308

Issue created by migration from https://trac.sagemath.org/ticket/26929

[embray]

comment:45

Retarging tickets optimistically to the next milestone. If you are responsible for this ticket (either its reporter or owner) and don't believe you are likely to complete this ticket before the next release (8.7) please retarget this ticket's milestone to sage-pending or sage-wishlist.

[rburing]

comment:46

This bug was also encountered on Ask SageMath. The workaround to restore the old behavior is

from sage.rings.polynomial.polynomial_quotient_ring import PolynomialQuotientRing_generic
PQ = PolynomialQuotientRing_generic(P, X^4+X+1, 't')
t = PQ.gen()

but of course the underlying issue should be addressed.

[mantepse]

comment:47

Is there any interest in this ticket? Should I rebase?

[embray]

comment:48

Moving all blocker/critical issues from 8.7 to 8.8.

[embray]

comment:49

Moving tickets from the Sage 8.8 milestone that have been actively worked on in the last six months to the next release milestone (optimistically).

[embray]

comment:50

Ticket retargeted after milestone closed

[seblabbe]

comment:52

Current branch has conflict with the current develop branch of Sage.

[mkoeppe]

comment:54

Setting new milestone based on a cursory review of ticket status, priority, and last modification date.

[mkoeppe]

comment:55

Setting a new milestone for this ticket based on a cursory review.