# Cyber-Physical Computation 2021/2022

## Introduction and objectives

Welcome to the webpage of the module "Cyber-Physical Computation", edition 2021/2022.

Cyber-physical systems are networks of computational devices that closely interact with physical processes in order to reach a prescribed goal; for example a desired velocity, a desired temperature or, more generally, a desired energy level. They range from small medical devices, such as pacemakers and insulin pumps, to networks of autonomous vehicles and district-wide smart grids. This module is devoted to such systems.

The main learning goal is two-fold: 1) to prepare the student to a
**disciplined** way of developing and analysing cyber-physical systems,
by presenting their **basic principles**, adequate **models of
computation**, and respective **tools**; 2) and to introduce the student
to the main limitations of the area's state-of-the-art
– via pedagogical illustrations extracted from real world-scenarios
involving e.g. cruise controllers, sampling algorithms, and timed
variants of concurrent algorithms.

At the end of the module, the student will:

- know the basic principles and representative models of cyber-physical computation;
- have a broad knowledge of languages, tools, and techniques for engineering cyber-physical systems;
- be proficient with the tools Uppaal and Lince, which cover model checking, testing, and simulation for cyber-physical systems;
- be able to understand in which ways the state-of-the-art (of cyber-physical computation and engineering) is limited, and the potential outcomes of solving these limitations.

## Syllabus

- Labelled transition systems, their role as semantic objects, and corresponding notions of equivalence;
- Timed labelled transition systems and corresponding notions of equivalence, composition, and synchronisation. Zeno behaviour;
- From theory to practice: the tool Uppaal;
- A while-language and its operational semantics;
- A hybrid while-language and its operational semantics;
- From theory to practice: the tool Lince;
- Cyber-physical behaviour as yet another computational effect: the notion of a monad, the hybrid monad, and monad combination.

## Summaries

16 Feb. 2022 | Introduction to the module and its dynamics (slides) |

23 Feb. 2022 | Labelled transition systems and their role as semantics objects. The Calculus of Communicating Systems (slides) |

25 Feb. 2022 | The semantics of CCS (slides). Exercises. |

02 Mar. 2022 | Observational Behaviour and Observational Equivalence (slides) |

04 Mar. 2022 | Continuation of the previous lecture. Exercises (slides) |

09 Mar. 2022 | Introduction to timed automata (slides). |

11 Mar. 2022 | Continuation of the previous lecture. Exercises (slides). |

16 Mar. 2022 | Observational equivalence for timed automata (slides). |

18 Mar. 2022 | Introduction to Uppaal. |

23 Mar. 2022 | Extra features of Uppaal. The logic CTL and its application to the verification of Timed Systems (slides). |

25 Mar. 2022 | Tackling the adventurers' problem with Uppaal (description of the problem). |

30 Mar. 2022 | Continuation of the previous lecture. |

06 Apr. 2022 | Recalling Haskell (file). |

08 Apr. 2022 | Continuation of the previous lecture (file). Presentation and discussion of the first practical assignment. |

20 Apr. 2022 | A simple While-language and its semantics (slides). |

27 Apr. 2022 | A hybrid While-language and its semantics (slides). |

29 Apr. 2022 | Continuation of the previous lecture (slides). |

04 May 2022 | A zoo of hybrid programs and common mistakes in hybrid programming (slides). |

06 May 2022 | Introduction to the simply-typed lambda-calculus(slides). |

13 May 2022 | Continuation of the previous lecture (slides). |

17 May 2022 | Integration of algebraic effects in lambda-calculus (slides). |

20 May 2022 | Contexts and tensorial strength. Exercises (slides). |

25 May 2022 | Several examples of monads at work (code). |

27 May 2022 | The Knight's quest and the Monty Hall problem (code). |

## Assessment

## Bibliography

Rajeev Alur and David L Dill.
A theory of timed automata.
*Theoretical computer science*, 126(2):183--235, 1994.
[ bib ]

Thomas A Henzinger.
The theory of hybrid automata.
In *Verification of digital and hybrid systems*, pages 265--292.
Springer, 2000.
[ bib ]

Glynn Winskel.
*The formal semantics of programming languages: an introduction*.
MIT press, 1993.
[ bib ]

Sergey Goncharov, Renato Neves, and José Proença.
Implementing hybrid semantics: From functional to imperative.
In *International Colloquium on Theoretical Aspects of
Computing*, pages 262--282. Springer, 2020.
[ bib ]

Miran Lipovaca.
*Learn you a haskell for great good!: a beginner's guide*.
no starch press, 2011.
[ bib ]

Philip Wadler.
Monads for functional programming.
In *International School on Advanced Functional Programming*,
pages 24--52. Springer, 1995.
[ bib ]

*This file was generated by
bibtex2html 1.99.*

### Supplementary bibliography

Bart Jacobs.
*Introduction to coalgebra*, volume 59.
Cambridge University Press, 2017.
[ bib ]

Chucky Ellison and Grigore Rosu.
An executable formal semantics of c with applications.
*ACM SIGPLAN Notices*, 47(1):533--544, 2012.
[ bib ]

*This file was generated by
bibtex2html 1.99.*

## Contact

The day and time for appointments is Wednesday afternoon (but please send an email the day before if you wish to meet). If you prefer you can also just send an email with your questions to Renato Neves