Series Termination Geometry

Series Termination Geometry formalizes the geometric conditions under which iterative, amplified, or open-ended sequences of actions, operators, or semantic updates must collapse to a finite, stable endpoint. The paper proves that admissibility, Perron-support constraints, gate isolation, curvature bounds, and semantic invariance jointly force termination after finitely many non-inert steps. Series termination is shown to be the dynamic manifestation of Stack closure: once termination invariants are satisfied, no further admissible evolution exists. This framework provides a precise geometric account of why infinite safe iteration is impossible in near-critical systems within the Einsteinian Stack.