FUNCTION: NcaAdd - sum of two elements of the nilCoxeter algebra

CALLING SEQUENCE:

NcaAdd(e_1, e_2)

NCA[NcaAdd](e_1, e_2)

PARAMETERS:

e_1, e_2 = any elements of the nilCoxeter algebra

SYNOPSIS:

• The NcaAdd function adds two elements of the nilCoxeter algebra.

• One can use instead the operator &@+.

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

EXAMPLES:

> with(NCA):
> a:=q + u/t*A[3,1,2]:
> b:=t - A[1,3,2]:
> NcaAdd(a, b);
 
                                     u A[3, 1, 2]
                (q + t) A[1, 2, 3] + ------------ - A[1, 3, 2]
                                           t
 
> a &@+ b;
 
                                     u A[3, 1, 2]
                (q + t) A[1, 2, 3] + ------------ - A[1, 3, 2]
                                           t