Definition: Admissible accessible decoder

After the access cut, the decoder receives exactly its declared accessible interface. It may use:

1. quantum registers in $A$;

2. fresh local ancillas in fixed states independent of the logical input, omitted registers, and external reference;

3. records generated from operations on its received interface;

4. deterministic classical feedforward.

It receives no omitted register, omitted-register syndrome, hidden encoding environment, input label, validation reference, or privileged simulator state. Every terminal branch has a specified logical qubit output.