This paper reports on a simpler and more powerful replacement for the principles for defining new constants that were previously provided in the various HOL implementations. We discuss the problems that the new principle is intended to solve and sketch the proofs that it is conservative and that it subsumes the earlier definitional principles. The new definitional principle for constants has been implemented in HOL4 and in ProofPower and has been adopted in OpenTheory and in the work of Kumar, Myreen and Owens on a fully verified implementation of HOL. Kumar et al. have formally verified that the new definitional principle is conservative with respect to the standard set theoretic semantics of HOL. We continue this line of thought with a look at the mechanisms for defining new types and consider potential improvements, one of which has now been adopted in OpenTheory.

中文翻译：

---

关于 HOL 中常量和类型的定义

本文报告了一种更简单、更强大的替代方法，用于定义以前在各种 HOL 实现中提供的定义新常量的原则。我们讨论了新原则旨在解决的问题，并概述了它是保守的并且包含了早期定义原则的证明。常数的新定义原则已在 HOL4 和 ProofPower 中实现，并已被 OpenTheory 以及 Kumar、Myreen 和 Owens 的工作采用，以充分验证 HOL 的实现。库马尔等人。已经正式验证了新的定义原则相对于 HOL 的标准集合理论语义是保守的。我们继续这一思路，看看定义新类型的机制并考虑潜在的改进，