HELP FOR: A package for the Hecke algebra.
CALLING SEQUENCE:
- HEKA[<function>](args)
- <function>(args)
-
SYNOPSIS:
- This package provides functions to work with the Hecke algebra of the
symmetric group. This algebra is generated by simple operators Ti's
satisfying braid relations and the Hecke relation:
Ti*Ti = (q1 + q2)*Ti - q1*q2
- The usual Hecke algebra is obtained by setting q1=q and q2=-1.
- A general element is expressed as a linear combination of A[perm], where
perm is a permutation, with arbitrary coefficients.
- Whenever there is a conflict between a function name in HEKA and
another name used in the same session, use the long form
HEKA[<function>].
- The available functions are:
- For help with a particular function do either ?HEKA[<function>] or
?HEKA,<function> where <function> is one from the above list.
- Instead of HekaAdd, HekaMinus, HekaMult, one can use in short
&?+ &?- &?*
EXAMPLES:
> with(HEKA):
> a:=q + u/t*A[3,1,2]:
> b:=t*A[2,1,3] - A[1,3,2]:
> HekaMult(a, b);
q t A[2, 1, 3] + (- q1 q2 u - q) A[1, 3, 2] + (q1 u + q2 u) A[3, 1, 2]
u A[3, 2, 1]
- ------------
t