Definition: Laboratory and external storage

At an observer event $\tau$, let $q_{\mathrm{lab}}(\tau )$ count delivered radiation, working ancillas, retained quantum records, and recovered output not yet returned.

Let $q_{\mathrm{buf}}(\tau )$ count emitted accessible radiation held by passive external suppliers. Any other permitted auxiliary quantum storage is counted separately in $q_{\mathrm{aux}}(\tau )$.

Define

and

The inaccessible remnant and external correctness reference are not observer storage. Radiation not yet emitted is not counted as an external radiation buffer.