#8581: Implement an uniform set for index infinite variable algebraic structure,
implement polynomial ring in infinite set of indeterminate with categories,
implement the Schubert base ring in y1, y2, y3, ...
-----------------------------+----------------------------------------------
   Reporter:  nborie         |       Owner:  nborie                             
     
       Type:  enhancement    |      Status:  needs_review                       
     
   Priority:  major          |   Milestone:  sage-5.0                           
     
  Component:  combinatorics  |    Keywords:  polynomial, infinite, Schubert, 
category
     Author:                 |    Upstream:  N/A                                
     
   Reviewer:                 |      Merged:                                     
     
Work_issues:                 |  
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Description changed by nborie:

Old description:

> This patch Implement a set with categories to index monomials of infinite
> indeterminate algebraic structure. There is 4 versions of this set :
> power of indeterminate can be negative or only positive and there is a
> dense and sparse implementation of the set (list/dictionary).
>
> From this set, there is an example of graded_algebras_with_basis which is
> the polynomial ring in infinite indeterminate.
>
> The Schubert base ring inherit from this example and changing 3 thing:
>  *  the name of the ring
>  *  the name of variable (y1, y2, y3, ...) for Schubert
>  *  A __call __ method for element which correspond to the specialization
>
> With this patch, one can do for example:
> {{{
> sage: from sage.combinat.multivariate_polynomials.schubert_base_ring
> import SchubertBaseRing
> sage: from sage.categories.examples.graded_algebras_with_basis import
> PolynomialRingInfiniteIndeterminate
> sage: S = SchubertBaseRing(ZZ); S
> Base ring for Schubbert polynomials in the variables y1, y2, y3, ... over
> Integer Ring
> sage: A = PolynomialRingInfiniteIndeterminate(S); A
> An example of graded algebra with basis: the polynomial ring in infinite
> indeterminate over Base ring for Schubbert polynomials in the variables
> y1, y2, y3, ... over Integer Ring
> sage: A.base_ring().an_element()*A.an_element()
> (1+2*y1+y1*y3^2*y4^3+3*y1^2) + (2+4*y1+2*y1*y3^2*y4^3+6*y1^2)*X1 +
> (1+2*y1+y1*y3^2*y4^3+3*y1^2)*X1*X3^2*X4^3 +
> (3+6*y1+3*y1*y3^2*y4^3+9*y1^2)*X1^2
> }}}
>
> This built the ambient space for Schubert polynomials which are
> polynomials in two infinite alphabet of indeterminate indexed by
> PositiveIntegers() (or NonNegativeIntegers()... setting this is easy...)

New description:

 This patch Implement a set with categories to index monomials of infinite
 indeterminate algebraic structure. There is 4 versions of this set : power
 of indeterminate can be negative or only positive and there is a dense and
 sparse implementation of the set (list/dictionary).

 From this set, there is an example of graded_algebras_with_basis which is
 the polynomial ring in infinite indeterminate.

 The Schubert base ring inherit from this example and changing 3 thing:
  *  the name of the ring
  *  the name of variable (y1, y2, y3, ...) for Schubert
  *  A __call __ method for element which correspond to the specialization

 With this patch, one can do for example:
 {{{
 sage: from sage.combinat.multivariate_polynomials.schubert_base_ring
 import SchubertBaseRing
 sage: from sage.categories.examples.graded_algebras_with_basis import
 PolynomialRingInfiniteIndeterminate
 sage: S = SchubertBaseRing(ZZ); S
 Base ring for Schubbert polynomials in the variables y1, y2, y3, ... over
 Integer Ring
 sage: A = PolynomialRingInfiniteIndeterminate(S); A
 An example of graded algebra with basis: the polynomial ring in infinite
 indeterminate over Base ring for Schubbert polynomials in the variables
 y1, y2, y3, ... over Integer Ring
 sage: A.base_ring().an_element()*A.an_element()
 (1+2*y1+y1*y3^2*y4^3+3*y1^2) + (2+4*y1+2*y1*y3^2*y4^3+6*y1^2)*X1 +
 (1+2*y1+y1*y3^2*y4^3+3*y1^2)*X1*X3^2*X4^3 +
 (3+6*y1+3*y1*y3^2*y4^3+9*y1^2)*X1^2
 }}}

 This built the ambient space for Schubert polynomials which are
 polynomials in two infinite alphabet of indeterminate indexed by
 PositiveIntegers() (or NonNegativeIntegers()... setting this is easy...)

 Will be followed by the Adrien's work on #6629

--

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8581#comment:4>
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