Model checking single agent behaviours by fluid approximation

In this paper we investigate a potential use of fluid approximation techniquesin the context of stochastic model checking of CSL formulae. We focus onproperties describing the behaviour of an individual agent in a (large) pop-ulation of agents, exploiting a limit result known as fast simulation. Inparticular, we will approximate the behaviour of a single agent with a time-inhomogeneous CTMC, which depends on the environment and on the otheragents only through the solution of the fluid differential equation, and modelcheck this process. In order to achieve this goal, we will present a novel pro-cedure to model check time-inhomogeneous CTMC against CSL formulae,investigating also the decidability of this model checking problem. We willthen prove the asymptotic correctness of our approach in terms of satisfia-bility of CSL formulae.