Benchmark forensics
The answer key is also an input to verification.
A formal proof can establish that a theorem follows from a formalization. It cannot by itself establish that the formalization faithfully captures the intended authority. So the verifier is pointed at specifications, graders, gold labels, and reference implementations too — and the misses are filed, in public where possible.
tau2-bench gold labels
Externally validatedFive banking ground-truth defects filed (#370–374); four fixed in v1.0.1. Re-grading moved every model's banking score.
v1.0.1 changelog →RuleArena reference answers
Public · pendingThe airline reference assumes a fee-minimising bag order the rules never state; 93/300 answers depend on it. Filed as issue #5 with the evidence.
RuleArena issue #5 →Vero reference specifications
Public · pendingA kernel-checked disproof of one reference spec, plus a reference implementation depending on sorryAx — 119 affected specs held rather than claimed. Issues #3/#4/#5/#7.
Vero issues →A kernel-green Lean corpus
ExperimentalAn adversarial semantic audit of 1,689 kernel-checked textbook formalizations found 12 major and 3 critical fidelity defects, with 4 counterexamples reproduced. Proof-checked is not the same as faithful.
Our own PyJWT formalization
Frozen localA drafted duplicate-header defect report against PyJWT was withdrawn within three hours and never sent: clause-basis mining flagged an unmapped RFC 7515 §4 clause permitting last-wins parsing. The missed clause was ours — the library was conformant. The same sweep found one internally inconsistent vector in the IETF cookbook corpus.
Other systems could do this too. The claim is narrower: these are measured, filed instances of the verifier overruling its own benchmark — one of them accepted and shipped upstream.