Language-theoretic classification of hypermedia paths

Paths are, and have been since the beginning, an important mechanism for organizing hypermedia documents. This note shows how a document defined as a (possibly infinite) collection of paths over content nodes can be succinctly expressed as a formal language. We show the relationship to earlier hypermedia models based on automata. The language-theoretic model can be used to implement path engines as parsers or recognizers. Different levels of path power require different classes of recognizing automata.