Regular Expressions for Languages over Infinite Alphabets
Michael Kaminski, Tony Tan · Fundamenta Informaticae · 2006
In this paper we introduce a notion of a regular expression over infinite alphabets and show that a language is definable by an infinite alphabet regular expression if and only if it is accepted by finite-state unification based automaton – a model of computation that is tightly related to other models of automata over infinite alphabets.