On the Structural Necessity of Relative Causal Closure V1

This work presents a formal, graph-theoretic analysis of the structural conditions under which persistence is describable in degradable systems. It proves that persistence within a causal reference frame necessarily implies the existence of an internal compensatory causal loop accessible in that frame. The result establishes a necessary condition for coherent causal description, is non-ontological, independent of physical laws, and identifies a structural limit to acyclic causal modeling. A minimal appendix demonstrates compatibility with thermodynamics without reliance on it.