To choose diagrams in amplitude calculation

The default is to choose all the Feynman diagrams in the amplitude calculation. To choose a few diagrams in the amplitude calculation, the user need to add the following line in the file "process.def".

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

where the diagram n1,n2,...n will be calculated and others will droped. n1, n2 ... are the order number of the diagrams, It can be found by looking at the generated diagrams. Therefor this option is added to the file "process.def" after all the Feynman diagrams generated. It is the same situation for the next option.