  A data language is a set of finite words defined on an infinite alphabet.
Data languages are used to express properties associated with data values
(domain defined over a countably infinite set). In this paper, we introduce set
augmented finite automata (SAFA), a new class of automata for expressing data
languages. We investigate the decision problems, closure properties, and
expressiveness of SAFA. We also study the deterministic variant of these
automata.
