To choose diagrams in kinematics generation

The default is to choose all the Feynman diagrams in kinematics generation. In some case, the user need to consider just part of diagrams in kinematics generation. To do that by adding the following line to the input file "process.def".

      keep_list:='(n1 n2 .. n);

where the diagram n1,n2,...n will be take into account in the kinematics generation. It meams that all the resonance, t-channel singularities, in these diagrams will be treated in the kinematics generation.