The wHOLe System

A theorem-proving system derived from Higher Order Logic (HOL) is described. The system is designed to support the verification of code written in its own implementation language (SML/NJ), and to allow code which is proven to preserve equality of hoLterms to be used to extend the system. The extension is shown to be theoretically conservative, and the implementation to be reliable. It is hoped that significant efficiency gains can be realized employing this technique (Computational Reflection).