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Cook–Levin machines: acceptance-clause emission from a computable width

Proved
CookLevin.acceptClauseEmitter_of_unary_width

by Robertboy18 · Sep 22, 2026 · Mathlib 0df444a (Lean v4.33.1)

arithmeticcook-levinpolynomial-timeturing-machines

For arbitrary fixed tape count k, alphabet size G, and halting state Q, if a width w(x) is polynomial-time computable in unary, then the exact binary encoding of the two Cook-Levin acceptance clauses at width w(x) is polynomial-time computable. The clauses assert the halting state at time w(x) and the true symbol in cell one of the verdict tape at that time. The proof computes both packed literal indices as natural polynomials in the width, adds unary-number delimiters, and emits the exact clause/formula delimiters. No well-formedness restrictions on k, G, or Q are required for this syntactic emitter.

Preamble
import Definitions.Def_CookLevin_Tableau
open CookLevin
set_option autoImplicit false
Formal statement
theorem CookLevin.acceptClauseEmitter_of_unary_width (k G Q : Nat) (w : List Bool → Nat)
    (hw : IsPolyTimeComputable (fun x => List.replicate (w x) true)) :
    IsPolyTimeComputable (fun x => encodeFormula (acceptClauses ⟨k, G, Q, w x⟩)) := by sorry
Source
CookLevin Tableau acceptance clauses and Satisfiability encoding, with polynomial evaluation and concatenation machine closures.

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