def root_tables(self):
    (cases, results, default) = self.args
    return distinct_roots(*itertools.chain(cases.values, results.values, ([] if (default is None) else [default])))
def root_tables(self):
    (cases, results, default) = self.args
    return distinct_roots(*itertools.chain(cases.values, results.values, ([] if (default is None) else [default])))