Complete-channel approximation corollary

Nonempty targets and existence of protocols are hypotheses of the corollary. Their construction remains separate from its proof. A nonempty extraction domain is not a nonempty domain of compatible transport realizations.

The coordinate normalization makes null slope one. It determines neither a calibrated physical speed nor clock and rod units. The arrival register uses absolute target coordinate (eq:arrival-target); the endpoint duration uses the displacement coordinate $\tau$. Their connection is supplied by the realization, not assumed from identical notation.