FUNCTION: Rd2Heka - calculate a product of generators

CALLING SEQUENCE:

Rd2Heka(rd)

Rd2Heka(rd, n)

HEKA[Rd2Heka](rd)

HEKA[Rd2Heka](rd, n)

PARAMETERS:

rd = any list denoting a decomposition

n = any positive integer denoting the degree of a symmetric group

SYNOPSIS:

• The Rd2Heka function calculates the product of the generators given by the decomposition rd. The product is taken in the Hecke algebra.

• If rd is reduced then Rd2Heka(rd)=SG['Rd2Perm'](rd), and otherwise it involves parameters q1 and q2.

• When the second argument is not present, n is the smallest possible degree.

• Whenever there is a conflict between the function name Rd2Heka and another name used in the same session, use the long form HEKA['Rd2Heka'].

EXAMPLES:

> with(HEKA):
> Rd2Heka([1,2,1], 5);
 
                               A[3, 2, 1, 4, 5]
 
> Rd2Heka([1,2,1]);
 
                                  A[3, 2, 1]
 
> Rd2Heka([1,2,1,2]);
 
                   - q1 q2 A[3, 1, 2] + (q1 + q2) A[3, 2, 1]