#14990: Implement algebraic closures of finite fields
-------------------------------------+-------------------------------------
       Reporter:  pbruin             |        Owner:
           Type:  enhancement        |       Status:  needs_review
       Priority:  major              |    Milestone:  sage-6.3
      Component:  algebra            |   Resolution:
       Keywords:  finite field       |    Merged in:
  algebraic closure                  |    Reviewers:
        Authors:  Peter Bruin        |  Work issues:
Report Upstream:  N/A                |       Commit:
         Branch:  u/pbruin/14990     |  fdd883792076e8cdb2b1ae7a15cfe28b36d653ca
   Dependencies:  #14958, #13214     |     Stopgaps:
-------------------------------------+-------------------------------------

Comment (by pbruin):

 Hi Vincent,
 > 1) I found that your explanation is rather vague: it is not clear if you
 speak about mathematics or the Sage implementation.
 Both: mathematically speaking, algebraic closures are not unique up to
 unique isomorphism unless you fix some standard model, and therefore we
 necessarily have a similar non-uniqueness in Sage reflecting this
 mathematical fact.  I tried to make clear how the mathematical fact
 influences the Sage implementation, but let me know if you have a concrete
 idea for improving this paragraph.
 > Moreover, this weirdness only concerns pseudo-Conway implementation
 (which is right now the only one).
 Certainly, that is why the new paragraph starts with "In the current
 implementation".
 > In a future, we might implement Jean-Pierre idea: deal with Conway
 polynomial or have a certified- non-random version of pseudo-Conway.
 Of course, but we are still in the present... 8-)

 (Actually, I'm sceptical about the possibility of defining "certified-non-
 random version of pseudo-Conway" in a way that would improve on the
 original Conway polynomials.  Besides, I would say that the "idea" of
 using Conway polynomials should be attributed to Conway!)
 > 2) It must absolutely be clear in the documentation of
 `.algebraic_closure` that the pickling is broken! This is the main entry
 point for users.
 OK, I'll add some explanation there too.  But I am against phrasing it as
 "pickling is broken"; we should really say that this is an inherent
 "feature" of the non-unicity of algebraic closures, at least until we
 support any standard model.
 > 3) Do you agree to add to the documentation the different weirdnesses I
 described in my comments ? (possibly in a TODO section)
 I don't see quickly which "weirdnesses" are still remaining, could you
 give me a list?

--
Ticket URL: <http://trac.sagemath.org/ticket/14990#comment:83>
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 http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.

Reply via email to