That would mean adding `operator.equivalent(a, b) -> bool` which would allow float to override the result and let `operator.equivalent_value(float("NaN"), float("NaN))` return True; luckily very few types would actually override the operation.
You misunderstand what's going on here. Python deliberately makes float('NaN') != float('NaN'), and in fact there's special code to ensure that behavior. Why? Because it's mandated by the IEEE 754 floating-point standard.
This bizarre behavior is often exploited by people exploring the
murkier corners of Python's behavior. Changing it is (sadly) not