We extend the propositional dynamic logic PDL of Fischer and Ladner with a restricted kind of recursive programs using the formalism of visibly pushdown automata (Alur, Madhusudan...
This paper is concerned with the universality problem for timed automata: given a timed automaton A, does A accept all timed words? Alur and Dill have shown that the universality p...
This paper illustrates a technique for specifying the detailed timing, logical operation, and compositional circuit design of digital circuits in terms of ordinary state machines w...
We study computer virology from an abstract point of view. Viruses and worms are self-replicating programs, whose constructions are essentially based on Kleene's second recurs...
In this paper we study the problem of deciding whether a regular path query over views in data-integration systems can be re-expressed without recursion. The problem becomes chall...