Safety as Computation: Certified Answer Reuse via Capability Closure in Task-Oriented Dialogue

TL;DR

This paper proposes a novel approach to task-oriented dialogue systems that uses safety certification as a primitive, enabling answer reuse through fixed-point closure computation, which improves efficiency and answer reliability.

Contribution

It introduces a capability closure-based safety certification paradigm and a Certified Answer Store with Pre-Answer Blocks for efficient, provably correct answer reuse.

Findings

Answers are computed in sub-millisecond time.

Redundant retrieval and generation are eliminated.

The system guarantees derivability of answers from prior state.

Abstract

We introduce a new paradigm for task-oriented dialogue systems: safety certification as a computational primitive for answer reuse. Current systems treat each turn independently, recomputing answers via retrieval or generation even when they are already derivable from prior state. We show that in capability-based systems, the safety certification step computes a fixed-point closure cl(At) that already contains every answer reachable from the current configuration. We operationalize this insight with a Certified Answer Store (CAS) augmented by Pre-Answer Blocks (PAB): at each certified turn, the system materializes all derivable follow-up answers together with minimal provenance witnesses. Subsequent queries are answered in sub-millisecond time via formal containment checks, eliminating redundant retrieval and generation.