Decidability results for hybrid automata often exploit subtle properties about dimensionality (number of continuous variables), and interaction between discrete transitions and continuous trajectories of variables. Thus, the decidability results often do not carry over to parallel compositions of hybrid automata, even when there is no communication other than the implicit synchronization of tim...

Two schema problems from the 1970s are examined, monadic recursion schemes and first-order recursion schemas. Research on these problems halted because they were shown to be equivalent to the problem of decidability of language equivalence between DPDA (deterministic pushdown automata). Recently a decidability proof for equivalence of DPDA was given by Sénizergues [10, 11], which therefore also...

In this paper, we study combining equational tree automata in two different senses: (1) whether decidability results about equational tree automata over disjoint theories E1 and E2 imply similar decidability results in the combined theory E1 ∪ E2; (2) checking emptiness of a language obtained from the Boolean combination of regular equational tree languages. We present a negative result for the...

The paper demonstrates how second-order quantiication and nite games can be exploited for deciding complicated propositional program logics like the propositional-Calculus with converse (C ?). This approach yields a new proof that C ? is in EXP T IME. Automata-theoretic technique is a very powerful and popular approach for deciding complicated propositional program logics 19, 20, 3]. The rst pa...

We extend dynamic logic of propositional assignments by adding an operator parallel composition that is inspired separation logics. provide axiomatization via reduction axioms, thereby establishing decidability. also prove the complexity both model checking and satisfiability problem stay in PSPACE.

We define and illustrate the expressiveness of the AB̄L fragment of the Epistemic Halpern–Shoham Logic as a specification language for multi-agent systems. We consider the model checking problem for systems against specifications given in the logic. We show its decidability by means of a novel technique that may be reused in other contexts for showing decidability of other logics based on interv...

Bisimulation quantifiers are a natural extension of modal logics. They preserve the bisimulation invariance of modal logic, while allowing monadic second-order expressivity. Unfortunately, it is not the case that extension by bisimulation quantifiers always preserves the decidability of a modal logic. Here we examine a general class of modal logics for which decidability is preserved under exte...

Recently Sénizergues showed decidability of the equivalence problem for deterministic pushown automata. The proof of decidability is two semi-decision procedures that do not give a complexity upper bound for the problem. Here we show that there is a simpler deterministic decision procedure that has a primitive recursive upper bound.