An explicit local apparatus dilation

This is a concrete finite-dimensional instance of dilation Stinespring,Watrous, not an appeal to a localization theorem. Its locations have already been fixed: $U_{\mathrm{B}}$ acts at $A$, and $U_L,U_R$ act at the respective wing events.

The environments are inaccessible to the operational output but are retained in the complete dilation ledger. For its spacetime support, they have declared local storage segments to the terminal horizon. Operational tracing is not physical annihilation.