PREA: Establishing Reality as a System Variable - The First Complete Theory–Practice–AI Architecture

Modern systems do not operate on reality but on interpretation. Because reality is not a defined, validated, or operationalized variable, instability emerges across all domains. This absence of a reality‑validation function produces a four‑fold blind gap: (1) Theory does not know the gap because it presupposes reality without defining it; (2) Practice cannot name the gap because it experiences symptoms without access to the underlying cause; (3) AI research does not see the gap because models process patterns, not reality; (4) Systems cannot measure the gap because reality is not a system variable. As a result, decisions become unstable, communication breaks, organizations lose orientation, processes drift, and AI systems hallucinate. All these phenomena share a single structural cause: the absence of a reality‑validation architecture. PREA introduces the first complete Theory–Practice–AI architecture by establishing reality as a system variable. It does so by defining reality, validating premises, and operationalizing reality, thereby stabilizing systems across domains. This paper closes the circle initiated with the identification of the structural argumentation gap in Lehmann (2026). With the completion of the PREA architecture, the discipline is concluded.