Walking on Data Words

International audienceWe see data words as sequences of letters with additional edges that connect pairs of positions carrying the same data value. We consider a natural model of automaton walking on data words, called Data Walking Automaton, and study its closure properties, expressiveness, and the complexity of paradigmatic problems. We prove that deterministic DWA are strictly included in non-deterministic DWA, that the former subclass is closed under all boolean operations, and that the latter class enjoys a decidable containment problem