Primary evidence
- StochBench: A Domain-Specific Benchmark for Stochastic Processes in LeanS1 · Primary research · Paper · 2026-09-08
- StochBench datasetS1 · Primary research · Dataset
The benchmark covers Markov chains, renewal processes, random walks, martingales, stopping times, queues, Brownian motion, stochastic calculus, weak convergence, Poisson processes and continuous-time Markov processes.
The StochBench paper introduced 450 Lean 4 problems in graduate stochastic processes paired with natural-language sources; the authors report that an Opus 4.8-based proof agent solved 157 of 450 targets within a 15-minute per-problem budget, a 34.9% proof rate.
The benchmark covers Markov chains, renewal processes, random walks, martingales, stopping times, queues, Brownian motion, stochastic calculus, weak convergence, Poisson processes and continuous-time Markov processes. Its released dataset distinguishes 114 direct formalizations from 336 abstracted targets that expose assumptions explicitly when the required stochastic-process infrastructure is not available in the fixed Lean/Mathlib environment.
Formal theorem-proving benchmarks can overstate general mathematical coverage when they concentrate on domains already well represented in proof libraries. StochBench makes domain breadth and library-support limitations part of the evaluation surface, providing a harder test of whether proof agents can operate in applied mathematics with substantial formalization gaps.
Significance rationale: StochBench is a field-level benchmark milestone because it moves Lean theorem-proving evaluation beyond predominantly competition and textbook-style mathematics into a broad graduate applied-mathematics domain, while explicitly representing the gap between direct formalization and abstraction needed when library support is incomplete.
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The arXiv research record defines the 450-problem benchmark, its stochastic-process scope and the reported 157/450 baseline under a 15-minute per-problem budget.
The public StochBench dataset exposes the informal statements, Lean statements, representation labels and stored proof records. E3 records artifact-level inspectability and does not imply an independent replay of the full baseline evaluation.
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