Proof of `Weighted d-CNF Satisfiability Is in A[1]`

groundedproofs/Lax496464Proofs/WHierarchy/Lemmas/WSatInA1/Final.lean · lax-496464

What this proof establishes

Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.

Read the Lean proof on GitHub

Description

p−WSat(d−CNF)∈A[1]p-WSat(d-CNF) ∈ A[1] (Flum–Grohe, Theorem 6.28). The reduction maps (α,k)(α, k) to the structure whose universe is the literal occurrences of αα plus a padding element zz, with the first occurrences of the variables (CC), the negative parts of the clauses as padded tuples (NN), and for every clause and every branch word b<dkb < d^k of the bounded search tree the pair of its negative part and the found hitting set of the positive parts of the clauses with that negative part (LrLr); and to the Σ1Σ_1-sentence ∃ x̄ w ȳ (Z w ∧ ⋀ C xᵢ ∧ ⋀_{j<i} ¬ xᵢ = xⱼ ∧ ⋀_t (¬ N v_t ∨ (Lr v_t y_t ∧ ⋀_j ⋁_i y_{t,j} = xᵢ))), tt ranging over the maps 0,…,d→x0,…,xk−1,w{0,…,d} → {x_0,…,x_{k-1},w}. It is computed in time O(Pk(k)3⋅∣x∣2)O(Pk(k)³ · |x|²).