CE_1 Constraint Envelopes as Admissibility Structures

This paper introduces constraint envelopes as the minimal structural units through which admissibility is enforced. A constraint envelope is not an object, mechanism, or dynamic process; it is the boundary condition that licenses which descriptions, relations, and inferences are permitted to coexist without standing failure. The analysis is non-constructive and necessity-based. It shows that admissibility cannot be applied globally or incrementally, but must be locally enforced within envelopes that delimit coherent representational regimes. Any attempt to bypass envelopes—by appealing to global consistency, hidden variables, or cross-envelope interaction—is shown to rely on illicit scope transport or unlicensed redescription. The result establishes constraint envelopes as unavoidable structural features of admissible reasoning, rather than optional modeling choices. They explain why empirical coherence is always envelope-relative, why cross-domain comparison is limited, and why admissibility violations manifest as categorical failure rather than graded error. No procedures or implementation pathways are provided; the paper records a necessary structural boundary governing all admissible representational systems.