StateWise: Teaching Language Models to Track and Obey Evolving Constraints in Multi-Turn Dialogue

Abstract

Users of conversational assistants rarely state all requirements up front: they add constraints, amend them, withdraw them, digress, and return. Instruction-tuned LLMs fail here in two ways: active constraints stop being honored as turns accumulate (persistence failure), and withdrawn constraints keep being enacted (relapse). The only existing repair we know of is an external ledger that re-injects a compiled specification every turn. We propose StateWise, a self-improving approach that teaches a single LLM to maintain its own revisable constraint state, a typed state with tombstones for revoked constraints, so persistence and relapse are measured by executable checkers and ground-truth states are compiled for free. StateWise fine-tunes the LLM on two complementary skills, summarizing a dialogue into its constraint state and responding conditioned on that state, then self-trains on its own trajectories, keeping only turns that pass an exact round-trip check against the compiled state. This teaches 7-8B models to track the state almost perfectly but, surprisingly, not to obey it: on Llama-3.1-8B every supervised variant roughly doubles relapse. We therefore add a preference stage on self-generated relapse contrasts, where the rejected response enacts a revoked rule and the chosen one passes the round-trip check. On two backbones with held-out constraint families and unseen phrasings, StateWise cuts relapse by 8-22 points relative to supervised self-training, lifts conversation success by 8-19 points over the backbone, and beats an oracle compiled-ledger baseline on relapse with no inference-time scaffolding. We also characterize the recipe's cost on general instruction-following benchmarks and study weight interpolation as a mitigation.