FUNCTION: Rd2BnIdca - calculate a product of generators

CALLING SEQUENCE:

Rd2BnIdca(rd)

Rd2BnIdca(rd, n)

BNA[Rd2BnIdca](rd)

BNA[Rd2BnIdca](rd, n)

PARAMETERS:

rd = any list denoting a decomposition

n = any positive integer

SYNOPSIS:

• The Rd2BnIdca function calculates the product of the generators given by the decomposition rd (0 denotes the special generator). The product is taken in the Bn-idCoxeter algebra.

• If rd is reduced then Rd2BnIdca(rd)=BN['BnRd2Code'](rd), and otherwise there is a possible extra sign.

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

• Whenever there is a conflict between the function name Rd2BnIdca and another name used in the same session, use the long form BNA['Rd2BnIdca'].

EXAMPLES:

> with(BNA):
> Rd2BnIdca([0,1,0,1], 5);
 
                                B[1, 3, 0, 0, 0]
 
> Rd2BnIdca([0,1,0,1]);
 
                                     B[1, 3]
 
> Rd2BnIdca([1,0,1,0,1]);
 
                                   - B[1, 3]
> Rd2BnIdca([0,0]);
 
                                      B[1]