Theorem · conditional complexity transfer

FPRD-LT-T01

Conditional NP transfer through a compact poDFA action

Exact statement

If an nn-state L-trivial instance admits a polynomial-time computable faithful poDFA action ρ:Mop↪TP\rho:M^{\mathrm{op}}\hookrightarrow T_P of polynomial degree, explicit generator images, and a computable target code tft_f that equals ρ(f)\rho(f) for positive instances and lies outside ρ(M)\rho(M) for negative instances, then membership is in NP and positive instances have word certificates of length at most ∣P∣(∣P∣+1)/2|P|(|P|+1)/2.

StatusProved conditionally; the compact dual representation is not known in general
External reviewThe poDFA representative bound is a published MFCS 2024 result; no external review of this conditional FPRD transfer is recorded.

Context

Ryzhikov and Wolf prove a quadratic representative bound when the R-trivial action is already supplied as a poDFA. The theorem states exactly what is needed to transfer that result to the compact L-trivial input.

Hypotheses and scope

  • ∣P∣|P| is polynomial in the original input size.
  • The action is faithful and its generator transformations are explicitly computable.
  • A target code tft_f is computable even when f∉Mf\notin M, equals ρ(f)\rho(f) when f∈Mf\in M, and lies outside ρ(M)\rho(M) otherwise.
  • A partial order witnessing the poDFA property is available.

Proof or evidence

Injectivity plus the total target-code condition preserves both positive and negative membership. The published poDFA bound supplies a quadratic-length representative, which can be guessed, evaluated in the explicit action, and reversed for multiplication in the original monoid.

Verification notes

The target is an arbitrary transformation of Q and may lie outside M, so the revised statement no longer applies rho to an element outside its domain. Each representation and size assumption remains explicit.

Limitations

  • The theorem is not an unconditional NP upper bound for the original problem.
  • The right regular action may have exponentially many states.

Open work

Construct a polynomial-degree faithful action of the opposite monoid or prove that no uniform construction exists.