'Checks if a permutation is even.
Examples
>>> from sympy.combinatorics.permutations import Permutation
>>> p = Permutation([0, 1, 2, 3])
>>> p.is_even
True
>>> p = Permutation([3, 2, 1, 0])
>>> p.is_even
True
See Also
is_odd'

@property
def is_even(self):

    return (not self.is_odd)
