The channel causal-cut criterion

Thus an uncounted control wire, capacity flag, or transport register that is an ancestor of an event is inside its boundary. If an external geometric decision is a specified function only of the state functional on that event interface and common declared labels, equal interface data give the same decision. This last assertion is substitution into that function, not a claim that the nonlinear coupling itself is a channel.

An input-dependent initialization or encoding is also part of the network. Hiding it outside the ancestor calculation would change the claimed cut.