 The propagation of gravitational energy according to general relativity apparently involves strongly nonseparable processes, since gravitational energy cannot be localized (it does not contribute to the stress-energy tensor defined at each point of spacetime as do other forms of energy). But even a non-locally-defined gravitational energy will still be supervenient upon the metric tensor defined at each point of the spacetime, and so the process of its propagation will be weakly separable.