State identification for labeled transition systems with inputs and outputs

For Finite State Machines (FSMs) a rich testing theory has been developed to discover aspects of their behavior and ensure correct functioning. Although this frequently used, e.g. check conformance protocol implementations, its applicability is limited by restrictions FSMs, in which inputs outputs alternate, are determined the previous input state. Labeled Transition Systems with (LTSs), as studied ioco theory, provide richer framework for component oriented systems, but lack algorithms test generation from FSM theory. In article, we propose an algorithm fundamental problem state identification during LTSs. Our direct generalization well-known computing adaptive distinguishing sequences FSMs proposed Lee Yannakakis. deal so-called compatible states, states that cannot be distinguished. Analogous result Yannakakis, prove if exists distinguishes all pairs (incompatible) LTS, our will find one. practice, such perfect tests typically do not exist. However, experiments implementation on collection (both academic industrial) benchmarks, produced still distinguish at least 99% incompatible pairs.