#7301: Gale Ryser theorem
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   Reporter:  ncohen         |       Owner:  mhansen     
       Type:  enhancement    |      Status:  needs_review
   Priority:  major          |   Milestone:  sage-4.3    
  Component:  combinatorics  |    Keywords:              
Work_issues:                 |      Author:              
   Upstream:  N/A            |    Reviewer:              
     Merged:                 |  
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Comment(by ncohen):

 Hello everybody !!! Well, concerning the wording issue, I believe that it
 is correct in this case, or that at least it depends on communities,
 especially, when one looks at the code : "the conjugate of p2 dominates
 p1" is written "p2.conjugate().dominates(p1), so surely I am not the only
 one to give these definitions to these words :-)

 The other issue seems for you to expect more than just a solution : you
 are both talking about the complete enumeration of the matrices
 corresponding to these criteria, and through Linear Programming I can olny
 give you a simple solution, as solvers are not that bright on the
 enumeration side... Would you happen to have a reference for this
 algorithm ? I was onnly able to find a proof to show one matrix existed,
 but nothing about enumerating them. I also have to admit that if writing
 this function was quick enough because I knew what I needed and how to use
 it, I may not have enough time available too look for a new ( and possibly
 long ) algorithm and implement it.

 Do you feel like this algorithm is totally useless as it is, or could it
 be possible to take this function and create a ticket to move it to a
 enumeration problem ?

 Besides, your friend was talking about "different subsets of numbers".
 Well, I only met this problem for 0-1 matrices and I assume your are not
 talking about replacing 0 by x and 1 by y... Do you mean that there is a
 version of this theorem working simultaneously for several types of
 different variables (with two partitions per type of variable, etc...)  ??
 This would interest me very much !!

 Thank you for your interest !

 Nathann

-- 
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/7301#comment:12>
Sage <http://www.sagemath.org>
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