C.16:15b - C.29 mathematical-lens use relation

If a mathematical lens depends on a measurement, recover the C.16 measurand, Scale, model, calibration, work, uncertainty, result episteme, and comparability basis first. C.29 may then state the lens-use admissibility claim; it does not construct the measurement, make values comparable, or provide provenance. A.10/G.6 retain provenance and B.3 retains assurance.