# Lab Lunch talk by Vashti Galpin

Hybridising PEPA and beyond

PEPA is a quantitative process algebra which has both a stochastic
discrete semantic interpretation as continuous-time Markov chains
and a deterministic continuous (fluid-flow) semantic interpretation
as ordinary differential equations. I will describe how we have
developed a hybrid semantics for PEPA combining both stochastic and
deterministic behaviour, using parameterised semantics with
transition-driven stochastic hybrid automata as our semantic target.
In this approach, actions are classified as stochastic or deterministic
in advance, and hence it can be considered a static approach. I will
also briefly describe my current work on hybrid semantics for Bio-PEPA
which takes a more dynamic approach in classifying reactions.