%0 Book Section %@ %A Acciai, Lucia %A Boreale, Michele %A De Nicola, Rocco %B Formal Techniques for Distributed Systems (FMOODS/FORTE 2011) %D 2011 %E Bruni, Roberto %E Dingel, Juergen %F eprints:420 %I Springer %K probabilistic transition systems – linear time – testing equivalence – safety %P 29-43 %S Lecture Notes in Computer Science %T Linear-Time and May-Testing in a Probabilistic Reactive Setting %U http://eprints.imtlucca.it/420/ %V 6722 %X We consider reactive probabilistic labelled transition systems (rplts), a model where internal choices are refined by probabilistic choices. In this setting, we study the relationship between linear-time and may-testing semantics, where an angelic view of nondeterminism is taken. Building on the model of d-trees of Cleaveland et al., we first introduce a clean model of probabilistic may-testing, based on simple concepts from measure theory. In particular, we define a probability space where statements of the form “p may pass test o” naturally correspond to measurable events. We then obtain an observer-independent characterization of the may-testing preorder, based on comparing the probability of sets of traces, rather than of individual traces. This entails that may-testing is strictly finer than linear-time semantics. Next, we characterize the may-testing preorder in terms of the probability of satisfying safety properties, expressed as languages of infinite trees rather than traces. We then identify a significative subclass of rplts where linear and may-testing semantics do coincide: these are the separated rplts, where actions are partitioned into probabilistic and nondeterministic ones, and at each state only one type is available. %Z © IFIP International Federation for Information Processing 2011