'Gets the size of the subset.
Examples
>>> from sympy.combinatorics.subsets import Subset
>>> a = Subset([\'c\', \'d\'], [\'a\', \'b\', \'c\', \'d\'])
>>> a.size
2
See Also
subset, superset, superset_size, cardinality'

@property
def size(self):

    return len(self.subset)
