\documentclass{article} \usepackage[preprint,nonatbib]{neurips_2025} \usepackage[utf8]{inputenc} % \usepackage[T1]{fontenc} % \usepackage{hyperref} % \usepackage{url} % \usepackage{booktabs} % \usepackage{amsfonts} % \usepackage{nicefrac} % \usepackage{microtype} % \usepackage{xcolor} % \usepackage{enumitem} \usepackage{graphicx} \usepackage{multirow} \usepackage{amsmath} \usepackage{amssymb} \usepackage{wasysym} \usepackage{wrapfig} \usepackage{makecell} \usepackage{mathtools} \usepackage{amsthm} \usepackage{multirow} \usepackage{booktabs} \usepackage{bussproofs} \usepackage{comment} \usepackage{enumitem} \usepackage{soul} % \usepackage{fontawesome5} \usepackage{epigraph} \newcommand{\zxh}[1]{{\color{purple}#1}} \setlength{\epigraphwidth}{0.5\textwidth} \definecolor{keywordcolor}{rgb}{0.7, 0.1, 0.1} % \definecolor{tacticcolor}{rgb}{0.0, 0.1, 0.6} % \definecolor{commentcolor}{rgb}{0.4, 0.4, 0.4} % \definecolor{symbolcolor}{rgb}{0.0, 0.1, 0.6} % \definecolor{sortcolor}{rgb}{0.1, 0.5, 0.1} % \definecolor{attributecolor}{rgb}{0.7, 0.1, 0.1} % \usepackage{listings} \def\lstlanguagefiles{lstlean.tex} \lstset{ language=lean, inputencoding=utf8, extendedchars=true, moredelim=[is][\colorbox{yellow}]{「}{」}, } \newcommand\bigforall{\mbox{\Large $\mathsurround0pt\forall$}} \theoremstyle{plain} \newtheorem{theorem}{Theorem}[section] \newtheorem{proposition}[theorem]{Proposition} \newtheorem{lemma}[theorem]{Lemma} \newtheorem{corollary}[theorem]{Corollary} \theoremstyle{definition} \newtheorem{definition}[theorem]{Definition} \newtheorem{assumption}[theorem]{Assumption} \theoremstyle{remark} \newtheorem{remark}[theorem]{Remark} \title{Beyond Theorem Proving: Formulation, Framework and Benchmark for Formal Problem-Solving} \author{Qi Liu, Xinhao Zheng, Renqiu Xia, Xingzhi Qi, Qinxiang Cao$^{*}$, Junchi Yan$^{*\dagger}$ \\ Sch. of Computer Science \& Sch. of Artificial Intelligence, Shanghai Jiao Tong University \\ \small{\texttt{\{purewhite,void\_zxh,xiarenqiu,dennyqi123,caoqinxiang,yanjunchi\}@sjtu.edu.cn}}\\\\\vspace{-10pt} \faGithub\ \small{\textcolor{magenta}{\url{https://github.com/Purewhite2019/formal_problem_solving_main}}} } \begin{document} \maketitle \begin{abstract} \renewcommand{\thefootnote}{} % \footnotetext{$^*$Correspondence. $^\dagger$Also affiliated with Shanghai Artificial Intelligence Laboratory.} % \renewcommand{\thefootnote}{\arabic{footnote}} As a seemingly self-explanatory task, \textit{problem-solving} has been a significant component of science and engineering. However, a general yet concrete formulation of problem-solving itself is missing. With the recent development of AI-based problem-solving agents, the demand for process-level verifiability is rapidly increasing yet underexplored. To fill these gaps, we present a principled formulation of problem-solving as a deterministic Markov decision process; a novel framework, \textbf{FPS} (\textit{\underline{F}ormal \underline{P}roblem-\underline{S}olving}), which utilizes existing FTP (formal theorem proving) environments to perform process-verified problem-solving; and \textbf{D-FPS} (\textit{\underline{D}eductive \underline{FPS}}), decoupling solving and answer verification for better human-alignment. The expressiveness, soundness and completeness of the frameworks are proven. We construct three benchmarks on problem-solving: \textbf{FormalMath500}, a formalization of a subset of the MATH500 benchmark; \textbf{MiniF2F-Solving} and \textbf{PutnamBench-Solving}, adaptations of FTP benchmarks MiniF2F and PutnamBench. For faithful, interpretable, and human-aligned evaluation, we propose \textbf{RPE} (\textit{\underline{R}estricted \underline{P}ropositional \underline{E}quivalence}), a symbolic approach to determine the \textit{correctness} of answers by formal verification. We evaluate four prevalent FTP models and two prompting methods as baselines, solving at most $23.77\%$ of FormalMath500, $27.47\%$ of MiniF2F-Solving, and $0.31\%$ of PutnamBench-Solving. \end{abstract} \vspace{-5mm} \epigraph{\small\textit{``In five minutes you will say that it is all so absurdly simple.''}\quad\quad\textit{--- Sherlock Holmes}}{Sir Arthur Conan Doyle, \textit{The Adventure of Dancing Men}} \vspace{-5mm} \begin{figure*}[t!] \centering \includegraphics[width=1\linewidth]{figs.FPS.pdf} \caption {Advantages of Formal Problem-Solving (FPS) and Deductive-FPS (D-FPS). \textbf{(a)} Even with sophisticated enhancements, LLMs may make reasoning flaws; \textbf{(b) (c)} FPS and D-FPS perform process-level verified problem-solving inside formal theorem proving environments; \textbf{(c)} D-FPS decouples answer deduction and validation to improve readability; \textbf{(d)} Informal answer checking suffer from false negatives on complex objects; \textbf{(e)} Restricted Propositional Equivalence (RPE) evaluates answers with symbolic heuristic in formal verification for stronger expressiveness.} \vspace{-15pt} \end{figure*} \input{introduction} \input{related} \input{method} \input{evaluation} \input{experiment} \input{conclusion} \bibliographystyle{IEEEtran} \bibliography{custom} { \small } \newpage \appendix \input{appendix.background} \input{appendix.related_works} \input{appendix.discussion_reasoning_pattern} \input{appendix.template} \input{appendix.exemplar_formulations} \input{appendix.proofs} \input{appendix.case_study_rpe} \input{appendix.benchmark} \input{appendix.case_study} \input{appendix.prompts} \input{appendix.env} \input{appendix.limitations} \input{appendix.ethics_statement} \typeout{get arXiv to do 4 passes: Label(s) may have changed. Rerun} \end{document}