**Preface**
*Mark with serene impartiality
The strife of things, and yet be comforted,
Knowing that by the chain causality
All separate existences are wed
Oscar Wilde, "Humanitad"*

This Festschrift is dedicated to Maciej Koutny on the occasion of his 60

It turns out that causality is a very complicated phenomenon. E.g. this book is 'caused' by Maciej's 60th birthday – even though its creation had preceded this remarkable occasion. This constitutes an instance of reverse temporal causality, whose formal modelling would undoubtedly require Petri nets with inhibitor arcs, contextual loops, and step semantics, not to mention the heavy mathematical artillery that Maciej uses so fluently. It is left to the reader to complete this formal model. ~~(I didn't get research funding for this.)~~

Apparently, the number 60 has some special significance, which I could not comprehend (being only 42, i.e. having accomplished only 70%). Hence, I have commissioned a personal research project to discover the secrets of 60, using the computational resources at my disposal. The experiment was conducted on a PC with a 64-bit Intel® Core™ i7-6700K 4.00GHz CPU with 4 cores (hyperthreaded) and 64Gb RAM. "60" was entered into Wikipedia's search box, and the results were carefully analysed. It turns out that 60 is:

- the natural number following 59 and preceding 61;
- being three times 20, it is called "three score";
- the number of seconds in a minute, and the number of minutes in an hour (a legacy of the Babylonian number system);
- a
*highly composite number*(a.k.a.*anti-prime*), as it has more divisors than any smaller positive integer has; - the sum of a pair of twin primes (29 + 31), the sum of four consecutive primes (11 + 13 + 17 + 19), adjacent to two primes (59 and 61), and the smallest number that is the sum of two odd primes in six ways (it takes a lot of courage being anti-prime surrounded by primes on all sides!);
- a
*unitary perfect number*, as it is equal to the sum of its proper*unitary divisors*, excluding the number itself; a divisor*d*of a number*n*is a unitary divisor if*d*and*n/d*share no common factors; - an
*abundant number*, as the sum of its proper divisors is greater than the number itself.

There are many more interesting and potentially relevant mathematical and non-mathematical facts about 60, but the penny dropped when I noticed this:

*The number of miles per hour an automobile accelerates to from rest (0-60) as one of the standard measurements of performance.*

The moment of truth! 60 is the standard performance measurement point, so we can now officially conclude that Maciej has been accelerating up to 60 impressively well (and continues to do so). Wikipedia also tells that the forthcoming *perfect number* is 496, which is the next goal for Maciej.

This book presents a collection of essays and papers written by Maciej's friends, colleagues, and disciples (these categories are not mutually exclusive – in fact, their overlaps are conjectured to be considerable). The contributions include personal essays as well as technical papers – both kinds of ingredients are essential for a balanced Festschrift.

I would like to thank everyone who contributed papers, supported or helped with the production of this Festschrift and with the organization of the presentation event. Finally, on behalf of all these people, I would like to congratulate Maciej on this occasion and wish him many happy returns!

September 2018

Newcastle upon Tyne

There is also a special issue of Scientific Annals of Computer Science dedicated to Maciej's 60th birthday.

Download the complete book as a single PDF (13.5MB)

- Cover (PDF 178KB)
- Editor (PDF 32KB)
- Preface (PDF 321KB)
- Contents (PDF 122KB)
- Author list (PDF 49KB)
- Multiparty Session Types in Distributed Systems with Migration (PDF 458KB)page 1

*Bogdan Aman and Gabriel Ciobanu* - Note on Simultaneous Choice-free Synthesis (PDF 379KB)page 13

*Eike Best, Raymond Devillers, Uli Schlachter, and Harro Wimmel* - Interval Semantics Generalized (PDF 335KB)page 20

*Thomas Chatain, Stefan Haar, Loïc Paulevé, and Stefan Schwoon* - Developing and Applying a Rewriting Framework for Timed Mobility (PDF 593KB)page 32

*Gabriel Ciobanu and Jason Steggles* - Can We Ever Stop Them? (PDF 258KB)page 50

*Jörg Desel* - Detecting and Mitigating Cyberattacks against Microservice-Based Controllers for the Digital Factory (Extended Abstract) (PDF 131KB)page 55

*Gabriele Gualandi, Emiliano Casalicchio, Emanuele Gabrielli, and Luigi Vincenzo Mancinia* - Causality's Revenge (PDF 238KB)page 58

*Werner A. Hofer* - Complexity of Checking Output-Determinacy in General Petri Nets (PDF 494KB)page 73

*Petr Jančar and Victor Khomenko* - Optimal Simulation and Maximally Concurrent Evolution - My Early Papers with Maciej Koutny (PDF 212KB)page 84

*Ryszard Janicki* - A Tribute to Maciej Koutny's Exceptional Scientific Leadership (PDF 225KB)page 90

*Kurt Jensen* - A Tale of High-Level Features in the Petri Box Calculus (PDF 147KB)page 91

*Hanna Klaudel, Franck Pommereau, and Elisabeth Pelz* - Partially Ordering Koutny's Traces (PDF 467KB)page 94

*Jetty Kleijn and Paul Smit* - A Brief Story of The Partnership (PDF 92KB)page 102

*Lukasz Mikulski* - How to Mix Concurrency and Choice and Not Explode (PDF 418KB)page 105

*Andrey Mokhov* - Memorable Occurrences (PDF 337KB)page 117

*Brian Randell* - Reflections on Our Collaboration and Friendship (PDF 255KB)page 122

*Grzegorz Rozenberg* - Reversibility, Event Structures and Petri Nets (PDF 106KB)page 124

*Irek Ulidowski* - Maciej Koutny 60: Congratulations! (PDF 77KB)page 127

*Wil M.P. van der Aalst* - Living in Terms of Causes and Effects (PDF 677KB)page 129

*Alex Yakovlev* - Benefit and Cost of Cloud Computing Security (PDF 155KB)page 143

*Wen Zeng and Vasileios Germanos*

Publisher: Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.

ISBN: 978-0-7017-0266-3, Publication date: 3rd September 2018

*Last modified 25/10/2018 by IGC*