Applicability Diagnostics in Fundamental Physics: A Functional Necessity Argument and a Fourteen-Case Calibration

Applicability assessment in fundamental physics faces a methodological problem distinct from whether a theory is true, confirmed, or mathematically coherent: what information must be recoverable if the licensing status of an individual physical claim is to be explicit and auditable? This paper develops a Functional Incompleteness Argument (FIA). Any such procedure must make recoverable (i) the requirements relative to which applicability is assessed, (ii) the warrant governing any support-relevant inferential transition—or the fact that none occurs—and (iii) whether those requirements and warrants are satisfied by the particular, versioned claim token. Omitting any one leaves the licensing status underdetermined in a distinct respect, and none of the three information kinds is recoverable from the other two. Functional equivalents of all three are therefore necessary, however they are implemented. The programme’s condition-type, transition, and token-level protocol chain is presented as one realisation, not the only possible one. The paper also defines a seven-signature pattern library and subjects it to a source-bound fourteen-case calibration. Under the sharpened v3 triggers, the pre-specified adjudications produce no newly earned firing: thirty-eight non-firings, five source-lock/non-assessment outcomes, and one unresolved circularity dependency. The calibration therefore does not support the earlier recurrence claim; instead, it constrains over-triggering and shows the methodological importance of explicit non-trigger boundaries. The necessity argument is independent of this calibration result, which tests the selectivity of the diagnostic vocabulary rather than the existence of the diagnostic function.