593 

   594 def successorsetverb(successorset):

   595     """ Return the verb summarizing the successorset

   596     """

   597     if not successorset:

   598         verb = 'pruned'

   599     elif len(successorset) == 1:

   600         verb = 'rewritten'

   601     else:

   602         verb = 'split'

   603     return verb