FUNCTION :  newxy - Compute new x,y mod N                            

CALLING SEQUENCE :  newxy(x,y,N)                                             

PARAMETERS :    x,y,N - integers such that N > 0 and (x,y,N)=1

SYNOPSIS :   Suppose (x,y,N)=1. This proc returns [x1,y1] such     
             (x1,y1), x1 == x mod N and y1 == y mod N.             

EXAMPLES :   

DISCUSSION :

SEE ALSO :