BIB-VERSION:: CS-TR-v2.0
          ID:: STAN//CS-TR-94-1517
       ENTRY:: August 09, 1994
ORGANIZATION:: Stanford University, Department of Computer Science
       TITLE:: Reactive, Generative and Stratified Models of Probabilistic
               Processes
        TYPE:: Technical Report
      AUTHOR:: Glabbeek, Rob J. van
      AUTHOR:: Smolka, Scott A.
      AUTHOR:: Steffen, Bernhard
        DATE:: July 1994
       PAGES:: 38
    ABSTRACT:: We introduce three models of probabilistic processes, namely,
               reactive, generative and stratified. These models are
               investigated within the context of PCCS, an extension of
               Milner's SCCS in which each summand of a process summation
               expression is guarded by a probability and the sum of these
               probabilities is 1. For each model we present a structural
               operational semantics of PCCS and a notion of bisimulation
               equivalence which we prove to be a congruence. We also show
               that the models form a hierarchy: the reactive model is
               derivable from the generative model by abstraction from the
               relative probabilities of different actions, and the
               generative model is derivable from the stratified model by
               abstraction from the purely probabilistic branching
               structure. Moreover the classical nonprobabilistic model is
               derivable from each of these models by abstraction from all
               probabilities.
       NOTES:: [Adminitrivia V1/Prg/19940809]
         END:: STAN//CS-TR-94-1517