[sage-devel] Faulty comparison between elements of quotient of multivariate polynomial ring

2016-05-30 Thread Alec Edgington
Hello, I've found an problem with comparison of elements in certain rings. Here is a piece of Sage to illustrate the issue: sage: R = PolynomialRing(GF(4), ('x', 'y')) sage: x, y = R.gens() sage: I = R.ideal([x^2 + y^2, x + y^3]) sage: S = R.quotient(I, 'ab') sage: a, b = S.gens() sage: c, d, e

[sage-devel] Re: Faulty comparison between elements of quotient of multivariate polynomial ring

2016-05-30 Thread Alec Edgington
On Monday, 30 May 2016 17:19:54 UTC+1, Nils Bruin wrote: > > Currently, u.__cmp__ uses the former to test equality, and it should > probably use the latter. The reasoning is argued in the code. It looks like > univariate polynomial ideals should just get a containment test implemented > Thanks,

[sage-devel] Re: Faulty comparison between elements of quotient of multivariate polynomial ring

2016-05-31 Thread Alec Edgington
Hi Simon, On Tuesday, May 31, 2016 at 9:18:15 AM UTC+1, Simon King wrote: > > Hi Alec, > > On 2016-05-30, Alec Edgington > > wrote: > > Thanks, that seems to be the problem. I also note the code comment "The > > whole quotient stuff relies in I.reduce(x) ret