5 research outputs found
DEQ:Equivalence Checker for Deterministic Register Automata
Register automata are one of the most studied automata models over infinite alphabets with applications in learning, systems modelling
and program verification. We present an equivalence checker for deterministic register automata, called DEQ, based on a recent polynomial-time
algorithm that employs group-theoretic techniques to achieve succinct
representations of the search space. We compare the performance of our
tool to other available implementations, notably in the learning library
RALib and nominal frameworks LOIS and NLambda
Game Semantics for Interface Middleweight Java
We consider an object calculus in which open terms interact with the environment through interfaces. The calculus is intended to capture the essence of contextual interactions of Middleweight Java code. Using game semantics, we provide fully abstract models for the induced notions of contextual approximation and equivalence. These are the first denotational models of this kind
SyTeCi: Automating Contextual Equivalence for Higher-Order Programs with References
International audienc
Reachability in pushdown register automata
We investigate reachability in pushdown automata over infinite alphabets. We show that, in terms of reachability/emptiness,
these machines can be faithfully represented using only 3r elements of the alphabet, where r is the number of registers. We settle the complexity of associated reachability/emptiness problems. In contrast to register automata, the emptiness problem for pushdown register automata is EXPTIME-complete, independent of the register
storage policy used. We also solve the global reachability problem by representing pushdown configurations with a special register automaton. Finally, we examine extensions of pushdown storage to higher orders and show that reachability is undecidable at order 2