Modal Interface Automata

Abstract

De Alfaro and Henzinger's Interface Automata (IA) and Nyman et al.'s recent combination IOMTS of IA and Larsen's Modal Transition Systems (MTS) are established frameworks for specifying interfaces of system components. However, neither IA nor IOMTS consider conjunction that is needed in practice when a component satisfies multiple interfaces, while Larsen's MTS-conjunction is not closed. In addition, IOMTS-parallel composition exhibits a compositionality defect. This paper defines conjunction on IA and MTS and proves the operators to be 'correct', i.e., the greatest lower bounds wrt. IA-and resp. MTS-refinement. As its main contribution, a novel interface theory called Modal Interface Automata (MIA) is introduced: MIA is a rich subset of IOMTS, is equipped with compositional parallel and conjunction operators, and allows a simpler embedding of IA than Nyman's. Thus, it fixes the shortcomings of related work, without restricting designers to deterministic interfaces as Raclet et al.'s modal interface theory does.

Error-pruning in interface automata

“…in [5] or modalities as e.g. in [10,13,2,11]. In the future, we will consider how these extensions work on the basis of our trace-based view we developed for the first variant.…”

Testing Preorders for dMTS: Deadlock- and the New Deadlock/Divergence-Testing

“…We start with some standard definitions, essentially taken from [14]. We assume a set Σ of visible actions and an additional internal action τ , write Σ τ for Σ ∪ {τ } and let a range over Σ and α over Σ τ .…”

“…Unfortunately, DMTS are difficult to handle; in particular, parallel composition on DMTSs has only been defined 20 years after their invention [3], and it seems that no results are known about it. Things are much easier and more intuitive in the subclass dMTS introduced in [14], where a disjunctive must-transition has only one action and just a choice of target states.…”

Towards an I/O Conformance Testing Theory for Software Product Lines based on Modal Interface Automata

“…The MTS depicted in Figure 2 are in fact MIAs, as they exhibit input-determinism and every input transition is mandatory. In deviation to Lüttgen and Vogler [15], we do not employ disjunctive MTS, as they are not needed for our purposes. Furthermore, we limit our considerations to MIAs without internal behaviors, i. e., τ transitions, which is no limitation, as all our results remain valid for MIAs with internal behavior.…”

“…• We consider a novel class of I/O-labeled modal transition systems, i. e., Modal Interface Automata (MIA) [15], instead of IOMTS. MIAs slightly restrict IOMTS to guarantee desirable refinement and compositionality properties.…”