Visored: A Controlled-Natural-Language Prover for LLM-Generated Mathematics
LLMs write mathematics in natural-language style but still hallucinate, and directly producing checked Lean from that style is hard. The paper asks how to give LLM workflows reliable mathematical feedback closer to how proofs are actually written.
Visored is a dependent-type-based prover with a controlled-natural-language surface that imitates mathematical prose. A rule-driven, cost-bounded automation layer discharges routine steps a textbook would omit. The pipeline elaborates CNL into a typed AST and Visored MIR, checks well-definedness, and transpiles an accepted proof into a Lean file built with lake. An LLM coding agent (Claude) drives the CLI, reading diagnostics and revising.
A coverage study on miniF2F-valid (244 problems) shows LLMs can use the CNL surface effectively with no prover-specific training data; the authors present it as a prototype and a lower bound on expressivity rather than a tuned pass rate.
