Constraint Architectures for Reliable LLM Systems: From Probabilistic Generators to Constrained Epistemic Decision Systems

This preprint develops architectural instantiations of the Constrained Informational Systems (CIS) framework in computational systems, with a focus on constraint placement, regime behavior, and system-level failure modes in large language models. Building on the CIS system class, the analysis examines how constraint location within layered architectures (generation, constraint, execution, verification, and authority boundaries) produces qualitatively distinct behavioral regimes. These include epistemic paralysis under excessive constraint, chaotic dissolution under insufficient constraint, and catastrophic over-coherence when constraint collapse reduces semantic plurality to a single dominant attractor. In large language models, these regimes manifest as recognizable failure patterns, including hallucination, brittle refusal, and overconfident convergence. The work reframes these behaviors as structural consequences of constraint configuration rather than model-intrinsic failures. A minimal operational model is introduced to illustrate how constraint magnitude and placement jointly shape system outputs under fixed generative conditions. The paper further specifies falsifiable hypotheses and outlines empirical pathways for evaluating constraint-induced regime transitions in deployed systems. This work does not extend the CIS system class. It makes explicit its architectural consequences and applies them to contemporary AI systems. Formalization of semantic entropy, basin stability, and empirical validation are deferred to subsequent work. This record includes a version-linked independent technical review. The review reflects an independent technical assessment and does not constitute endorsement or co-authorship. It references earlier draft versions (v1.4) but reflects iterative feedback with final alignment confirmed for v1.6. Independent technical review by Michael J. Cates ("Boundary Engineering / Execution-Boundary Framework"), included as a version-linked artifact.