In previous work we have developed a syntactic reduction of repeated reachability to reachability for finite state systems. This may lead to simpler and more uniform proofs for mo...
Visibly Pushdown Automata (VPA) are a special case of pushdown machines where the stack operations are driven by the input. In this paper, we consider VPA with two stacks, namely 2...
Higher-order pushdown systems (PDSs) generalise pushdown systems through the use of higher-order stacks, that is, a nested “stack of stacks” structure. These systems may be us...
Model-checking problems for PDL (propositional dynamic logic) and its extension PDL (which includes the intersection operator on programs) over various classes of infinite state sy...
We study languages of nested trees--structures obtained by augmenting trees with sets of nested jump-edges. These graphs can naturally model branching behaviors of pushdown program...