A macro COSY program will consist
of collectivisors, paths, processes and bodyreplicators appearing
between the word pair 
and .
Since after expansion of a macro program all its collectivisors disappear, the macro program should include at least one path or process or bodyreplicator, for the body of the basic program obtained by expansion to be non-empty. The syntax for macro programs is given by:
According to the above rules, collectivisors, macro paths, macro
processes and bodyreplicators may appear in any order, with the
exception that no collectivisor may appear after all the paths,
processes and bodyreplicators.