One output, two checks

Code behaviour
Run targeted tests and record the observed cases.
Historical claim
Read an independent historical source.
Evidence does not transfer
Correct arithmetic is not evidence that the adjacent comment is historically accurate.
One output, two checks One generated output contains different claims Code behaviour Does the routine meet its contract? Historical comment Did Note G use this recurrence? Targeted tests Evidence about behaviour Historical source Evidence about the comment evidence does not transfer Correct arithmetic is not evidence that the comment is accurate.