Drop-In Compatibility Without Property Regression: A Structural Admissibility Condition for Infrastructure-Bound Materials

Description This document establishes intrinsic drop-in compatibility without property regression as a structural admissibility condition for materials claiming seamless substitution within existing infrastructure. The analysis is non-constructive and does not disclose any compositions, blends, formulations, hardware designs, additive systems, or operating procedures. Instead, it formalizes a boundary condition under which a material claiming “drop-in,” “plug-and-play,” or “fully compatible” performance must preserve functional equivalence without hardware modification, co-solvent tuning, ratio optimization, or regression in seals, ignition, flow, or storage behavior. This condition constrains patentability at the level of enablement, inventive step, and industrial applicability and applies across all infrastructure-bound material domains.