#15408: corrections and improvements to `inner_plethysm` method in symmetric
functions
-------------------------------------+-------------------------------------
       Reporter:  zabrocki           |        Owner:
           Type:  defect             |       Status:  needs_review
       Priority:  major              |    Milestone:  sage-6.0
      Component:  combinatorics      |   Resolution:
       Keywords:  symmertic          |    Merged in:
  functions, inner plethysm          |    Reviewers:
        Authors:  Mike Zabrocki      |  Work issues:
Report Upstream:  N/A                |       Commit:
         Branch:                     |  cd4470b77781bdc17787a44d86b948d2c8ff0c75
  public/combinat/15408/zabrocki/inner_plethysm|     Stopgaps:
   Dependencies:                     |
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Comment (by zabrocki):

 Darij, my example of when the statement is when `g` and `h` are of the
 same degree, so my edits are only to try to make the doc string clearer.

 One of the reasons that I changed it was because I don't understand the
 meaning of the sentence "`f.inner_plethysm(g)` is a polynomial in the
 coefficients of `g`"  It should be a symmetric function, not a polynomial.
 The other phrase that appears throughout the docstring is "determine its
 values."   Unfortunately I don't understand what is meany by the
 ''values'' of a symmetric function.  My modifications of the docstring
 avoid this phrase because I don't understand what is intended by that
 phrase.

 I also think that there is something wrong in the sentence
 {{{
 we can think of the function `g` as the character of a representation of
 the
 general linear group, and hence (by Schur-Weyl duality) as the character
 of
 a representation `\rho` of the symmetric group `S_n`.
 }}}
 To my eye, `g` would not be a character of an S_n representation, but it
 would be a generating
 function for the character (Frobenius image of the character).  This is
 not a serious problem since the object of interest is the representation
 `\rho`, but  I find the use of Schur-Weyl duality an unnecessary
 complication in the explanation.

 Please read the docstring that I wrote.  Is it clearer?  Can you improve
 it more?

--
Ticket URL: <http://trac.sagemath.org/ticket/15408#comment:4>
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