Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-09-01 Thread Ralf Stephan
On Tuesday, August 30, 2016 at 5:44:59 PM UTC+2, Jeroen Demeyer wrote: > > Is it easy to actually do that? > https://trac.sagemath.org/ticket/21391 This catches add,mul,pow which is sufficient IMHO to communicate the issue. -- You received this message because you are subscribed to the

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-31 Thread Vincent Delecroix
On 31/08/16 02:36, Ralf Stephan wrote: On Tuesday, August 30, 2016 at 5:45:16 PM UTC+2, vdelecroix wrote: sage: x = SR.variable(domain = GF(3)) sage: n = SR.variable(domain = ZZ) This is good design(TM). The usage however duplicates Sage's polynomial rings,so why burden calculus with that?

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread Ralf Stephan
On Tuesday, August 30, 2016 at 5:45:16 PM UTC+2, vdelecroix wrote: > > sage: x = SR.variable(domain = GF(3)) > sage: n = SR.variable(domain = ZZ) > This is good design(TM). The usage however duplicates Sage's polynomial rings, so why burden calculus with that? The only other usage I can think

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread Ralf Stephan
In earlier times of Pynac, ie GiNaC was and is certainly including polynomial and pos.char. manipulations. I do not claim historical correctness wrt Sage. Thanks for correction. Jeroen, do you have a tricky counterexample? -- You received this message because you are subscribed to the Google

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread William Stein
On Tue, Aug 30, 2016 at 8:45 AM, Vincent Delecroix <20100.delecr...@gmail.com> wrote: > Hi Ralf, > > First of all, your opinon is more valuable than others since you are the > maintainer of Pynac. Perhaps my opinion is also worth something since I made up the name "Pynac" and wrote the first

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread Jeroen Demeyer
On 2016-08-30 17:28, Ralf Stephan wrote: I propose to make it an error to mix elements of rings with positive characteristics (or symbolic Mod) and symbolic variables. Is it easy to actually do that? -- You received this message because you are subscribed to the Google Groups "sage-devel"

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread Vincent Delecroix
Hi Ralf, First of all, your opinon is more valuable than others since you are the maintainer of Pynac. That being said, the constraint specification of symbolic variables in Sage is really poor. Ideally, we should be able to have symbolic computation more tightly linked to Sage parents. It

Re: [sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread William Stein
On Tue, Aug 30, 2016 at 8:28 AM, Ralf Stephan wrote: > As you know Pynac provides symbolic computation. In earlier times > this included polynomial manipulation and other things where Sage > has now dedicated and consistent algebraic structures. Can you clarify? Sage had and

[sage-devel] disallow mixing of pos.char.ring elements and symbolic variables

2016-08-30 Thread Ralf Stephan
As you know Pynac provides symbolic computation. In earlier times this included polynomial manipulation and other things where Sage has now dedicated and consistent algebraic structures. Pynac nowaday is mostly calculus. For this reason, and because I'm tired of trying to fix things that belong in