A kernel-checked Lean bridge connects OpenAI's subexponential bounded-width SAT theorem, applied at width 3 to the negation of ParityLifts' PositiveRateETH predicate. The bridge formalizes the SAT encoding conversion, machine simulation, polynomial overhead, and exponential-rate comparison.
Verified on the VPS at proof commit 81ec97cd2. The final theorem has no additional premises. Its axiom audit reports propext, Classical.choice, and Quot.sound.
Three connected statements
Reading points
Each reading point has a separate role: source theorem, formal specification, and proved result. Identifiers below are provisional pending registration in the RPI catalog.
For every width k ≥ 3, a fixed deterministic machine and width-dependent constants decide bounded-width CNF with a subexponential variable-count factor and polynomial encoding-length factor. OpenAI's Comparator checks exact_count_and_sat; original_sat_main is derived from it and kernel-checked in the final build.
A formal assertion that some positive exponential rate excludes all deterministic multitape 3-SAT deciders within the specified polynomial-times-exponential bound.
A verified implication applies OpenAI's SAT result to the ParityLifts formalization, constructing the required decider through a polynomial-overhead conversion and simulation.
Encoding correspondence. Convert ParityLifts' normalized 3-CNF inputs to OpenAI's exact canonical CNF bit encoding, preserving satisfiability, keeping the variable count bounded, and proving bit-for-bit equality with OpenAI’s encodeCNF (canonicalWord_eq). Conversion time is polynomial in the variable bound N (canonicalWordProgram_time_poly).
Machine translation. Represent OpenAI's primitive multitape machine in ParityLifts' finite-alphabet machine model with step-level correspondence.
Executable simulation. Construct a fixed ParityLifts FCode runner and prove polynomial resource overhead, yielding simulationHypothesis_proved.
Rate comparison. Bound OpenAI’s subexponential factor 2^(A · runtimeScale N) by an arbitrarily small positive exponential rate (runtimeFactor_expBound); incorporate polynomial converter and simulator costs using sat_code_rate, and refute PositiveRateETH with original_sat_main.
The kernel-checked conclusion is the negation of the specifically defined ParityLifts predicate PositiveRateETH. That predicate quantifies over deterministic finite-alphabet multitape machines deciding 3-SAT on ParityLifts' binary formula encoding, with a polynomial input-length factor and a positive exponential variable-count rate.
Comparison with standard textbook ETH is a separate semantic-fidelity review of the machine model, encoding, and quantifiers. The final statement’s meaning is fixed by the ParityLifts definitions; OpenAI’s MainTheorem enters as a kernel-checked proof term. OpenAI’s original paper and its precise Lean theorem have distinct complexity bounds; the bridge uses the Lean theorem.
Review focus: exact definition unfolding; machine and encoding faithfulness; quantifier order; rate preservation; and independent reproduction of the final kernel check.