

The structure of the \FORM~ \cite{FORM}  output is similar to those of
\REDUCE~ and 
\MATHEMATICA~ described above.  In the case of \FORM~ output a  
default summation  is not implemented 
and the user  must write  {\it UserSum()} anyway. 
An incomplete  sample of such procedure is written to 
 {\it  usr{\sc N}.frm}. In its turn this file is read  from  
{\it sum{\sc N}.frm}. Here N is the subprocess ordering number.
The denominator  factors (\ref{denominator}) are   presented in the form of functions 

{\tt den(-p1-p2,0,2)}
\\
where the first argument is a momentum of virtual particle, the second one is
the particle mass identifier, and the third one is the power of propagator. 

 
Unfortunately the \CompHEP~ group has not got too much  experience with 
the \FORM~ package 
and now this output cannot be commented well enough.
It was created as a result of D.Bardin's request and was used
by him and his co-authors for semi-analytic calculations.  Please, look at
these  files and try to understand how the \FORM~ output  can be used by you.
