FUNCTION :  ETA[POWERPq] -  q-expansion of power of q-series

CALLING SEQUENCE :  POWERPq(a,N,M)

PARAMETERS :
    a - q-series    
    N,M - positive integers

GLOBAL VARIABLES : 

SYNOPSIS :   
   Compute a^N to O(q^M) (where N>=0)

EXAMPLES :   

DISCUSSION :

SEE ALSO :