# A report onProcess calculus

In computer science, the process calculi (or process algebras) are a diverse family of related approaches for formally modelling concurrent systems.

- Process calculus

## Calculus of communicating systems

The calculus of communicating systems (CCS) is a process calculus introduced by Robin Milner around 1980 and the title of a book describing the calculus.

## Concurrency (computer science)

Ability of different parts or units of a program, algorithm, or problem to be executed out-of-order or in partial order, without affecting the final outcome.

Ability of different parts or units of a program, algorithm, or problem to be executed out-of-order or in partial order, without affecting the final outcome.

A number of mathematical models have been developed for general concurrent computation including Petri nets, process calculi, the parallel random-access machine model, the actor model and the Reo Coordination Language.

## Π-calculus

In theoretical computer science, the -calculus (or pi-calculus) is a process calculus.

## Actor model

Mathematical model of concurrent computation that treats actor as the universal primitive of concurrent computation.

Mathematical model of concurrent computation that treats actor as the universal primitive of concurrent computation.

Other concurrency systems (e.g., process calculi) can be modeled in the actor model using a two-phase commit protocol.

## Communicating sequential processes

Formal language for describing patterns of interaction in concurrent systems.

Formal language for describing patterns of interaction in concurrent systems.

It is a member of the family of mathematical theories of concurrency known as process algebras, or process calculi, based on message passing via channels.

## Concurrent computing

Form of computing in which several computations are executed concurrently—during overlapping time periods—instead of sequentially—with one completing before the next starts.

Form of computing in which several computations are executed concurrently—during overlapping time periods—instead of sequentially—with one completing before the next starts.

Beginning in the late 1970s, process calculi such as Calculus of Communicating Systems (CCS) and Communicating Sequential Processes (CSP) were developed to permit algebraic reasoning about systems composed of interacting components.

## Algebra of communicating processes

Algebraic approach to reasoning about concurrent systems.

Algebraic approach to reasoning about concurrent systems.

It is a member of the family of mathematical theories of concurrency known as process algebras or process calculi.

## Join-calculus

The join-calculus is a process calculus developed at INRIA.