Formalization of the Embedding Path Order for Lambda-Free Higher-Order Terms

October 19, 2018

Abstract

This Isabelle/HOL formalization defines the Embedding Path Order (EPO) for higher-order terms without lambda-abstraction and proves many useful properties about it. In contrast to the lambda-free recursive path orders, it does not fully coincide with RPO on first-order terms, but it is compatible with arbitrary higher-order contexts.