Verify a data operation without being fooled by your own checks — the discipline for migrations, dedups, reconciliations, mass-edits, backfills, and "is it actually done?" claims over real data. Chase mismatched numbers, verify the verifier, match by natural key, prove on a clone, confirm-before-delete. Use when the user runs /proof or is about to run or trust a destructive or large-scale data operation.
