def inner_product(self, x, y):
"""
Faster to reimplement than to use natural representations.
def inner_product(self, x, y):
"""
Faster to reimplement than to use natural representations.
def inner_product(self, x, y):
r"""
Half of the trace inner product.
def inner_product(self, x, y):
r"""
Half of the trace inner product.