On Weak Modal Compatibility, Refinement, and the MIO Workbench

Abstract

Building on the theory of modal I/O automata (MIOs) by Larsen et al. we introduce a new compatibility notion called weak modal compatibility. As an important property of behavioral interface theories we prove that weak modal compatibility is preserved under weak modal refinement. Furthermore, we organize and compare different notions of refinement and compatibility to give an easily-accessible overview. Finally, we describe the MIO Workbench, an Eclipse-based editor and verification tool for modal I/O automata, which implements various refinement, compatibility and composition notions and is able to depict the results of verification directly on the graphical representation of MIOsrelations or state pairs in the positive and erroneous paths in the negative case.

A Modal Specification Approach for On-Demand Medical Systems

“…There are many di erent types of re nement relations between MIOAs [24,7]. In our setting, we adopt the weak modal re nement relation [7], which ensures that the observable behavior of an implementation (e.g., actual medical device) re nes the speci cation (e.g., app requirements).…”

Nondeterministic Modal Interfaces

“…Interface theories [2,7,8,16,17,22] support the component-based design of concurrent systems and offer a semantic framework for, e.g., software contracts [1] and web services [5]. Several such theories are based on de Alfaro and Henzinger's Interface Automata (IA) [11], whose distinguishing feature is a parallel composition on labelled transition systems with inputs and outputs, where receiving an unexpected input is regarded as an error, i.e., a communication mismatch.…”

“…Several such theories are based on de Alfaro and Henzinger's Interface Automata (IA) [11], whose distinguishing feature is a parallel composition on labelled transition systems with inputs and outputs, where receiving an unexpected input is regarded as an error, i.e., a communication mismatch. All states are pruned from which entering an error state cannot be prevented by the environment, rather than leaving the parallel composition fully undefined as in [2].…”

“…In a refinement of an interface, all required behaviour must be preserved and no disallowed behaviour may be added. Whereas in IA outputs are optional, they may now be enforced in theories combining IA and MTS, such as Nyman et al's IOMTS [16], Bauer et al's MIO [2], Raclet et al 's Modal Interfaces (MI) [22] and our Modal Interface Automata (MIA) [17,18]. In this paper we extend MI to nondeterministic systems, yielding the most general approach to date and permitting new applications, e.g., for dealing with races in networks.…”

“…This is accompanied by a hiding operator for scoping actions as in [19]. These operators together are more expressive than the binary parallel composition of IA, which is used in [2,16,17,18]. We also develop a quotienting operator as a kind of inverse of parallel composition .…”