Abstract
Generative systems rank outputs probabilistically but do not inherently exclude inadmissible ones. As a result, substantial computation may be spent constructing candidates that violate hard constraints and are rejected only after full generation. We present a controlled study comparing post-hoc validation with constraint-first generation, where constraints are applied during candidate construction. Early pruning reduces invalid-path exploration, retries, and generation steps while maintaining or improving success rates. An adaptive variant further reduces search by incorporating feedback from prior constraint violations to restrict future admissible candidates. These results demonstrate that externally enforced, prefix-applicable constraints can restructure search by eliminating infeasible trajectories before they are fully explored. One-Sentence Claim: Externally enforced constraints, when applied during generation rather than after, transform search from rejection over a full space to construction within a feasible subset.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
pham, thom, "External Constraints as Search-Space Reduction in Generative Systems A Proof-of-Concept Study of Early Pruning vs Post-Hoc Validation", Technical Disclosure Commons, (April 16, 2026)
https://www.tdcommons.org/dpubs_series/9821