FUNCTION: Rd2Idca - calculate a product of generators

CALLING SEQUENCE:

Rd2Idca(rd)

Rd2Idca(rd, n)

IDCA[Rd2Idca](rd)

IDCA[Rd2Idca](rd, n)

PARAMETERS:

rd = any list denoting a decomposition

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

SYNOPSIS:

• The Rd2Idca function calculates the product of the generators given by the decomposition rd. The product is taken in the idCoxeter algebra.

• If rd is reduced then Rd2Idca(rd)=SG['Rd2Perm'](rd).

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

• Whenever there is a conflict between the function name Rd2Idca and another name used in the same session, use the long form IDCA['Rd2Idca'].

EXAMPLES:

> with(IDCA):
> Rd2Idca([1,2,1], 5);
 
                                 A[3, 2, 1, 4, 5]
 
> Rd2Idca([1,2,1]);
 
                                    A[3, 2, 1]
 
> Rd2Idca([1,2,1,2]);
 
                                  - A[3, 2, 1]