Leo-II is an automated theorem prover for classical higher-order logic. The prover has pioneered cooperative higher-order–first-order proof automation, it has influenced the development of the TPTP THF infrastructure for higher-order logic, and it has been applied in a wide array of problems. Leo-II may also be called in proof assistants as an external aid tool to save user effort. For this it is crucial that Leo-II returns proof information in a standardised syntax, so that these proofs can eventually be transformed and verified within proof assistants. Recent progress in this direction is reported for the Isabelle/HOL system.

中文翻译：

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高阶证明者 Leo-II

Leo-II 是经典高阶逻辑的自动定理证明器。证明者开创了协作式高阶一阶证明自动化的先河，它影响了高阶逻辑的 TPTP THF 基础设施的发展，并已应用于广泛的问题中。Leo-II 也可能被称为证明助手，作为一种外部辅助工具，以节省用户的工作量。为此，Leo-II 以标准化语法返回证明信息至关重要，以便这些证明最终可以在证明助手中进行转换和验证。Isabelle/HOL 系统在这个方向上取得了最新进展。