Uniform Labeled Transition Systems for Nondeterministic, Probabilistic, and Stochastic Process Calculi

TL;DR

This paper introduces ULTraS, a generalized labeled transition system framework that unifies the semantics of nondeterministic, probabilistic, and stochastic process calculi, enhancing modeling flexibility.

Contribution

It presents ULTraS as a unified semantic model capable of representing various process calculi with different types of nondeterminism and randomness.

Findings

ULTraS can model nondeterministic, probabilistic, and stochastic processes.

The framework provides a natural semantics for CSP-like languages.

ULTraS extends traditional labeled transition systems to incorporate reachability distributions.

Abstract

Labeled transition systems are typically used to represent the behavior of nondeterministic processes, with labeled transitions defining a one-step state to-state reachability relation. This model has been recently made more general by modifying the transition relation in such a way that it associates with any source state and transition label a reachability distribution, i.e., a function mapping each possible target state to a value of some domain that expresses the degree of one-step reachability of that target state. In this extended abstract, we show how the resulting model, called ULTraS from Uniform Labeled Transition System, can be naturally used to give semantics to a fully nondeterministic, a fully probabilistic, and a fully stochastic variant of a CSP-like process language.