They talk about some examples in their research.
> “Specifically, we initialized the DeepSeek-Prover using the DeepSeekMath-Base 7B model (Shao et al., 2024). Initially, the model struggled to convert informal math problems into formal statements. To address this, we fine-tuned the DeepSeek-Prover model using the MMA dataset (Jiang et al., 2023), which comprises formal statements from Lean 4’s mathlib2 that were back-translated into natural language problem descriptions by GPT-4. We then instructed the model to translate these natural language problems into formal statements in Lean 4 using a structured approach.”
Section 3.1 in https://arxiv.org/html/2405.14333v1
