FUNCTION: Bna2Table - convert an element of any Bn-algebra into a table

CALLING SEQUENCE:

Bna2Table(e)

BNA[Bna2Table](e)

PARAMETERS:

e = any element of any Bn-algebra

SYNOPSIS:

• The Bna2Table function converts an element of any Bn-algebra into a table. The table is indexed by codes of Bn and each entry corresponding to a code cod is the coefficient of B[cod] in e.

• This function can be useful if one wants to act either on coefficients or on codes. For instance, one can use the map function to act on coefficients.

• Whenever there is a conflict between the function name Bna2Table and another name used in the same session, use the long form BNA['Bna2Table'].

EXAMPLES:

> with(BNA):
> t := Bna2Table((x1+x2)*B[0,2,1] + x1^2*B[0,2,2] + B[0,0,0]);
 
                       t := table([
                              [0, 2, 1] = x1 + x2
                                            2
                              [0, 2, 2] = x1
                              [0, 0, 0] = 1
                            ])
 
> t := map(ToX, t);
 
                      t := table([
                             [0, 2, 1] = X[1, 3, 2]
                             [0, 2, 2] = X[3, 1, 2]
                             [0, 0, 0] = X[1]
                           ])
 
> Table2Bna(t);
 
     X[1, 3, 2] B[0, 2, 1] + X[3, 1, 2] B[0, 2, 2] + X[1] B[0, 0, 0]