A User Interface for Controlling Term Rewriting Based on Computing-as-Editing Paradigm

On a logically structured document, such as a formal proof, pieces of information are related by various kinds of constraint. Computing-as-editing paradigm (CAEP) was previously proposed as a principle for designing environments for editing such documents. In this paradigm, the process of editing a document is considered to include setting and solving constraints, and constraint solving is considered as computing. In this work, based on this paradigm, we developed a user interface for interactively controlling term rewriting. In former CAEP-based systems that use plain text, it is di cult to handle problems that require a large amount of information to be displayed. In this work, we designed an HTML-based document format to increase readability of documents, which enables us to describe term rewriting on hypertext. Documents in this format can be edited under an environment implemented on a common text editor. We also developed a technique for controlling term rewriting by extending di erence matching and rippling. We newly introduced patterns like regular expressions that can be speci ed as a goal of rewriting. Our document format supports tags for specifying rewrite relations and patterns. Term rewriting is performed when rewrite relations are solved as constraints on our editing environment.