Skip to content
Preprint

Constraint-First Reasoning: A Training-Free Protocol for Exploiting Answer-Space Constraints in Mathematical Problem Solving

Aug 2026 · 0 citations
Computer Science

TL;DR

This work introduces Constraint-First Reasoning (CFR), a training-free two-stage prompting protocol that improves direct CoT on multiple backbones and positions CFR as a targeted test-time intervention whose benefit depends on recoverable constraints and reliable Stage 1 extraction.

Abstract

Large language models can derive a plausible mathematical object yet still violate explicit requirements--for example, by omitting a modular reduction, returning a non-integer, or using the wrong encoded answer form. We introduce Constraint-First Reasoning (CFR), a training-free two-stage prompting protocol: Stage 1 extracts and summarizes constraints entailed by the problem, and Stage 2 solves while checking intermediate and final results against that summary. Routed-CFR activates the two-stage protocol only when a text-only regex router detects restrictive cues; otherwise it uses direct chain-of-thought (CoT). Across AIME, CMIMC, BRUMO, and AIMO_AMC, the method improves direct CoT on multiple backbones. We further report convention-controlled routing experiments, matched prompting baselines, problem-level paired tests, decoding robustness, constraint-quality audits, total-token accounting, and an OlympiadBench evaluation. These analyses position CFR as a targeted test-time intervention whose benefit depends on recoverable constraints and reliable Stage 1 extraction, rather than as a general-purpose replacement for mathematical reasoning.

View source

Similar papers

Open access Aug 2026

TRACE-QA: Task-routed constraint elimination for auditable multi-agent question answering

The proposed TRACE-QA, a training-free multi-agent protocol that routes each instance to a sparse set of reasoning operators, constructs option-blind necessity constraints, audits every candidate in a structured elimination ledger, revisits risky eliminations through global risk-aware rescue, and aggregates role-specialized judge votes, supports constraint-guided elimination as an auditable alternative to answer-first debate.

Jiaxin Lu, Hao Chen, Yan-Cheng Zhu et al. · 0 citations
Preprint Jul 2026

Search, Fail, Recover: A Training Framework for Correction-Aware Reasoning

Many reasoning tasks are not well described by a single left-to-right chain: a solver may need to pursue a plausible branch, observe delayed failure, and return to the latest prefix that can still be completed. We introduce Pyligent, a training and inference framework inspired by the Diligent Learner formulation that represents reasoning as validated search over partial solution chains. A task validator labels generated continuations and failures, and the resulting search trees are converted into supervised targets for three actions: continue, finish, and backtrack, with optional traces that summarize abandoned branches. We evaluate Pyligent on a hidden directed graph task designed to isolate delayed-failure recovery, and on structured reasoning domains with exact validators, including $4{\times}4$ Sudoku, Sudoku with reasoning traces, and Blocksworld. Compared with gold-only supervised fine-tuning, Pyligent improves solve rate by $72.7$ percentage points on hidden graphs, by $17$ and $18$ points on mixed and expert Sudoku, by $27$ and $14$ points on mixed and expert Sudoku with reasoning traces, and by $13$ points on Blocksworld. These results suggest that explicit failed-branch supervision can teach useful recovery behavior beyond imitation of polished solution chains.

Dmitry N. Beresnev, Vladimir Makharev, Roman Khalikov et al. · 1 citation
Conference 2026

From Literals to Atomic Constraints: Generalising Conflict-Driven Clause Learning for Constraint Programming

This work presents the first systematic analysis of how leading LCG solvers maintain their SAT encodings, based on source-code inspection and developer correspondence, and proposes a native CDCL framework for CP, replacing SAT literals with atomic constraints, enabling conflict analysis, nogood learning, and nogood propagation directly at the CP level.

Imko Marijnissen, Maarten Flippo, Emir Demirovi'c · 0 citations
Preprint Jul 2026

MIRA-Math: A Benchmark for Minimal Information Requesting and Mathematical Reasoning

Mathematical reasoning benchmarks typically provide all facts needed to solve each problem, while interactive benchmarks often mix reasoning with tools, retrieval, and long-horizon dialogue. We introduce MIRA-Math, a benchmark for a narrower diagnostic capability: solving mathematical problems whose full latent state has a unique answer, but whose solver-facing view is missing exactly one necessary atomic fact. The solver must request the missing information in natural language under a strict budget and then integrate the returned fact into an exact final answer. A fixed constrained LLM responder sees only the dataset-provided atomic fact and must either offer the quoted fact when the request matches it, or decline otherwise. Thus, instance generation, typed hint specifications, validation, and final-answer verification are deterministic, while request metrics are measured under a fixed LLM-mediated responder channel. MIRA-Math contains 2{,}310 generated instances from 22 typed mathematical families spanning algebra, probability, linear systems, discrete structures, signal processing, Markov chains, circuits, interpolation, and numerical boundary-value problems. Experiments across frontier and small models show that request success and final-answer accuracy are separable: models may ask for the right fact yet fail the downstream computation, or fail before obtaining the canonical hint. We release generators, verifiers, prompts, run metadata, and dataset documentation to support reproducible evaluation of minimal information requesting in mathematical reasoning.

Charbel Al Bateh, S. Saab · 0 citations
Preprint Jul 2026

Relay-Bench: Evaluating LLMs on Multi-Domain Reasoning Chains

Introducing Relay-Bench, an unsaturated, holistic, text-only benchmark that measures LLMs'ability to complete an assortment of tasks from distinct domains in a single prompt. The leading model, GPT-5.5 (xHigh), scores 43.3%. The test set entirely consists of composite problems: groups of single-domain subproblems that are strung together into challenges that require reasoning across multiple domains in combination. Many of these problems then have layers of complexity added through prompt encoding and deliberate context bloat. Domains tested include visual reasoning, coding, math, information extraction (with a focus on web search), problem-solving, general knowledge, and data analysis. No restrictions are imposed outside of the model harness, and models are explicitly encouraged to leverage code-execution, web searches, and all available tools. All problems are composed of two to thirteen subproblems and do not require multi-modal input or output.

Liam Swayne · 0 citations
2025

Beyond Oracle: Verifier-Supervision for Instruction Hierarchy in Reasoning and Instruction-Tuned LLMs

A unified supervision framework is introduced that embeds programmatically verifiable checkers into synthesized instruction-conflict instances, enabling alignment without oracle labels or reasoning traces, supporting both instruction-tuned and reasoning models.

Sian-Yao Huang, Li-Hsien Chang, Che-Yu Lin et al. · 4 citations