FUNCTION :  ETA[Ffind] -  check whether on pole is at oo

CALLING SEQUENCE :  Ffind(etaprod,N)

PARAMETERS :      
                  -            

GLOBAL VARIABLES : 

SYNOPSIS :   
     Returns 1 if etaprod is in F ie. only  negative valence at ioo = 1/N
     (GAMMA_0(N))

EXAMPLES :   

DISCUSSION :

SEE ALSO :