# Process algebra with strategic interleaving

## TL;DR

This paper extends process algebra ACP to incorporate interleaving strategies, such as process-scheduling policies, enabling more accurate modeling of systems with both arbitrary and strategy-based parallel process interleaving.

## Contribution

It introduces a new extension of ACP that models interleaving strategies, with proven properties like elimination, conservativity, and unique expansion.

## Key findings

- Extended ACP with interleaving strategies
- Proved elimination and conservative extension properties
- Supports modeling of hardware/software system behaviors

## Abstract

In process algebras such as ACP (Algebra of Communicating Processes), parallel processes are considered to be interleaved in an arbitrary way. In the case of multi-threading as found in contemporary programming languages, parallel processes are actually interleaved according to some interleaving strategy. An interleaving strategy is what is called a process-scheduling policy in the field of operating systems. In many systems, for instance hardware/software systems, we have to do with both parallel processes that may best be considered to be interleaved in an arbitrary way and parallel processes that may best be considered to be interleaved according to some interleaving strategy. Therefore, we extend ACP in this paper with the latter form of interleaving. The established properties of the extension concerned include an elimination property, a conservative extension property, and a unique expansion property.