Steward asked whether we can do something about the recurring class other than
name it. This is the mechanical part of the answer.
THE CLASS: four times in three days a passing check certified a property of the
CODE while claiming a property of the RESULT, each found by a person looking.
Every one tested a predicate NECESSARY but not SUFFICIENT for the property —
quotes-present ⊂ inference-survives; answer-non-empty ⊂ answer-produced;
no-heading-says-limitations ⊂ no-collected-limitations-section.
WHY THE POSITIVE CONTROLS MISSED IT: the fixtures were derived from the CHECK
('what makes this regex fail?') rather than from the PROPERTY ('what makes this
claim false?'). A control built from the check's own vocabulary inherits its
blind spot by construction — same shape as the recorded drift-pattern that a
control built by EXTRACTION leaks by construction.
THE GATE: a check must return DIFFERENT verdicts on two REAL artifacts, one known
to have the property and one known to lack it. Same verdict on both means it has
discriminated nothing, however many synthetic fixtures it passes. Real artifacts,
because a synthetic negative is written by the same hand as the check.
DEMONSTRATED, not asserted: the gate is run against the §3.3 pattern AS SHIPPED,
and rejects it — flagged=False on both the package (which has a collected
limitations section, Part VII) and the ruling (which has none). It discriminated
nothing while passing five synthetic fixtures. The current pattern passes.
Residue stated in the code rather than implied: a heading naming no topic
('## Part VII') defeats every wordlist, and the gate prints that it does. Passing
is not a §2a verdict; §2a stays in Kernel §4's judgement.
