#1819: move crypto.mq.MPolynomialSystem somewhere else
-----------------------------------+----------------------------------------
   Reporter:  malb                 |       Owner:  malb        
       Type:  enhancement          |      Status:  needs_review
   Priority:  major                |   Milestone:  sage-4.6.2  
  Component:  commutative algebra  |    Keywords:              
     Author:  Martin Albrecht      |    Upstream:  N/A         
   Reviewer:                       |      Merged:              
Work_issues:                       |  
-----------------------------------+----------------------------------------

Comment(by malb):

 Replying to [comment:16 vbraun]:
 > I don't see that anywhere in the `MPolynomialIdeal` class. Correct me if
 I'm wrong,
 > but the chosen generators and their order is immutable.

 Yep.

 > Even when computing a Groebner basis, the generators are not replaced by
 this much
 > more useful basis.

 But the GB is cached and used for "interesting" operations.

 > On the other hand, there are methods like `basis_is_groebner()` which
 are obviously
 > basis-dependent.

 This was the compromise reached to (a) keep the notion that ideals are
 different objects than their generators and to (b) still allow to query
 some information about the basis. We should have separated stuff back then
 perhaps. In any case, it was this method's name which sparked the debate
 we're having between William and myself.

 > It seems to me that Sage implements ideals very much as an immutable
 sequence of
 > polynomials with some methods attached.

 I'd say: it attempts to present a view on ideals which abstracts away
 chosen bases but with varying success.

 > The individual methods do, of course, need Groebner bases but they never
 change the > underlying sequence of polynomials.

 But e.g. `intersection()` and `reduce()` actually use the GB and not the
 provided basis, they are methods on the ideal and not on the generating
 set. Some other methods are less clear such as `basis_is_groebner()` and
 `interreduced_basis()`. These could perhaps be moved to
 `PolynomialSequence`.

 > I am aware that the ideals implicitly contain the term order, though I
 found that a somewhat mixed blessing in #10708.

 I wouldn't say this is because of the containment of term orderings but
 because of lack of care dealing with them?

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/1819#comment:17>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/sage-trac?hl=en.

Reply via email to