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proof_induced_measure

Function proof_induced_measure 

Source
pub fn proof_induced_measure(n_steps: usize) -> Vec<u64>
Expand description

The ⟹ direction of the characterization: any checkable refutation of n_steps steps induces a Lyapunov measure — rank the steps in descending order. The induced trajectory is a valid Lyapunov function of size n_steps, so the minimum measure cost μ*(F) ≤ (min proof size).

Combined with the ⟸ theorem (proof_from_measure: proof size ≤ L·w), this gives the CHARACTERIZATION μ*(F) = Θ(min proof size) — the measure framework is equivalent to the proof framework, so a lower bound on the measure cost IS a proof-size lower bound. That equivalence is the rigorous foundation of the “no bounded measure ⟹ no short proof” direction (the prize), stated honestly: it makes measure lower bounds and proof lower bounds the same problem, rather than giving a new technique to prove either.