n-1
FUNCTION :  qseries[aqprod] - the product (1-a)(1-aq)..(1-aq   )
    
CALLING SEQUENCE :  aqprod(a,q,n);
    
PARAMETERS :   a,q - names
               n   - integer
   
SYNOPSIS :   
   
 aqprod(a,q,n) returns the product                                      
   
                                                n-1
             (a)  =  (a;q)  = (1-a)(1-aq)..(1-aq   ),
                n         n   
 where n is a given positive integer. Here a and q are names, variables,
 or constants. If n=0 then 1 is returned. 

CHANGES :
  1.3: o can now handle negative n
   
EXAMPLES :   
   
> with(qseries):
> aqprod(q,q,6);
                      2         3         4         5         6
           (1 - q) (-q  + 1) (-q  + 1) (-q  + 1) (-q  + 1) (-q  + 1)
> aqprod(z,q,3);
                                               2
                         (1 - z) (-q z + 1) (-q  z + 1)
> aqprod(z,q,0);
                                       1
> aqprod(z,q,-3);
                                         6
                                        q
                      - ----------------------------------
                                     /      2 \ /      3 \
                         3           |     q  | |     q  |
                        z  (1 - q/z) |1 - ----| |1 - ----|
                                     \     z  / \     z  /
SEE  ALSO :