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SchurRings :: toE

toE -- Elementary symmetric (e-) basis representation

Synopsis

Description

Given a symmetric function f, the function toE yields a representation of f as a polynomial in the elementary symmetric functions.

If f is an element of a Schur ring S then the output fe is an element of the Symmetric ring associated to S (see symmetricRing).

i1 : R = symmetricRing 7;
i2 : toE(h_3*e_3)

      3                2
o2 = e e  - 2e e e  + e
      1 3     1 2 3    3

o2 : R
i3 : S = schurRing(s,4)

o3 = S

o3 : SchurRing
i4 : toE S_{3,2,1}

               2    2
o4 = e e e  - e  - e e
      1 2 3    3    1 4

o4 : QQ[e ..e , p ..p , h ..h ]
         1   4   1   4   1   4

This also works over tensor products of Symmetric/Schur rings.

i5 : R = schurRing(r, 4, EHPVariables => (a,b,c));
i6 : S = schurRing(R, s, 2, EHPVariables => (x,y,z));
i7 : T = schurRing(S, t, 3);
i8 : A = symmetricRing T;
i9 : f = (r_1+s_1+t_1)^2

o9 = t  + t    + (2r  s  + 2r s  )t  + (s  + s    + 2r s  + (r  +
      2    1,1      () 1     1 ()  1     2    1,1     1 1     2  
     ------------------------------------------------------------------------
     r   )s  )t
      1,1  ()  ()

o9 : T
i10 : toE f

       2                    2            2
o10 = e  + (2x  + 2a )e  + x  + 2a x  + a
       1      1     1  1    1     1 1    1

o10 : A

See also

Ways to use toE :

For the programmer

The object toE is a method function.