Human–AI Symbiosis: Relational Alignment in Domains of Extreme Physical Irreversibility

This paper proposes Level 4 Human-AI Symbiosis (L4), a relational alignment framework for domains of extreme physical irreversibility where errors cannot be corrected ex post. In such domains, alignment cannot depend solely on intrinsic model properties but must be architecturally instantiated through verifiable dependency between AI capabilities and responsible humans. We formalize V(H,S,t), a continuous link function decomposed into four orthogonal components, stepped degradation D0-D3 with ISO 14971 risk-based thresholds, and three variants of Critical Capability Gating. A Conditional Safety Proposition with explicit guarantee hierarchy is introduced. The framework complements Guaranteed Safe AI by introducing human-dependent runtime verification. Regulatory fit with the EU AI Act and Product Liability Directive 2024 is analyzed, identifying a critical window 2026-2027. Developed in dialogue with AI systems; the originating idea and philosophical core are the author's.