CE_7 Constraint Envelopes Are Not Empirically Detectable

This paper shows that constraint envelopes cannot be identified, measured, or inferred through empirical observation. Because envelopes function as admissibility boundaries rather than as objects or processes, any attempt to detect them empirically collapses into illicit reification or retrospective fitting. The analysis demonstrates that observational signatures, statistical regularities, or experimental asymmetries attributed to envelopes are always internal to an already-licensed representational regime. Treating such features as evidence for an envelope mistakes a boundary condition for an empirical cause. Once this confusion is removed, no observational procedure remains that could distinguish the presence or absence of an envelope. The result clarifies why admissibility constraints are not discoverable by experiment and cannot be validated post hoc. Constraint envelopes operate prior to and independently of empirical inquiry. The paper introduces no tests or detection schemes; it records the necessity that envelopes remain structurally invisible to observation while governing what observations are admissible.