Definition · finite-cut communication invariant

FPRD-D42

Cut-response system and response dimension

Exact statement

A finite cut-response system records the answer beta(p,c) for each past p and possible continuation c. Its response dimension is log2 of the number of distinct response rows, separating the information needed for readiness across a continuation family from the replay support used by any one completed continuation.

StatusDefined self-containedly and connected exactly to residual rows
External reviewNo documented external or specialist review of this FPRD result is recorded.

Context

Replay support is pointwise, whereas a prefix must remain ready for an entire family of continuations. The response table isolates exactly the information shared across that family.

Definitions

  • The response row of a past p is the vector of beta(p,c) over the selected continuation family.
  • Response dimension is log2 of the number of distinct response rows; the unrounded value is useful even when the row count is not a power of two.
  • For languages, beta(p,c)=1_L(pc); allowing every continuation recovers full right-residual equivalence.

Proof or evidence

The public proof note gives the exact factorization theorem, the language specialization, and a finite audit over every Boolean response matrix up to four by four.

Verification notes

The definition was checked against finite Myhill--Nerode tests, deterministic one-way messages, T150 replay support, and T151 response profiles.

Limitations

  • The invariant depends on the chosen cut families when they are finite restrictions.
  • It measures retained answer information, not update radius, allocation, degree, or access latency.
  • No novelty claim is made for the communication-matrix formulation.

Open work

Extend the finite-horizon scaffold capacity bound to richer stationary frontier presentations.