# Models of Concurrent Systems

##### Course with SWS 2/2/0 (lecture/exercise/practical) in SS 2022

Lecturer

SWS

• 2/2/0

Modules

Examination method

• Oral exam

Matrix channel

### News

• We offer two dates one date for oral examinations this semester, Thursday July 21 and (fully booked) Tuesday August 2. You can book an appointment for an oral examination with our secretary via e-mail.
• Upon request and polls among the participants we have moved our sessions from Tuesdays and Wednesdays DS3 to Tuesdays and Wednesdays DS4, taking effect on April 12, 2022.
• Please refer to Dates and Material to infer the room, which is also announced via the Matrix chat channel.
• Permanent rooms for the new time slots are going to be implemented soon.

### Course Description

Modern computer systems are often multi-threaded or even fully distributed over several machines and geographical locations. Instead of the well-known sequential computational models (e.g., Turing machines, $\lambda$-calculus, etc.) the key notion for describing concurrent computations is that of a /process/. In this course, we study several phenomena occurring in concurrent computations by means of process calculi, for which we will define and analyze their formal semantics. As one of the key aspects we ask when two processes are considered to be equivalent. Subsequently, we give an (incomplete) list of topics we strive throughout the course.

• From sequential to parallel processes (LTS, CCS)
• Bisimulation and Coinduction
• From sequential to concurrent processes (Petri nets)
• Mobile processes (the $\pi$-calculus)
• Expressive power of process calculi
• Data-Aware Processes

### Contact

If you have questions regarding the course, feel free to ask in the matrix chat or via email to the teacher of the course.

### Schedule and Location

The course is taught in two sessions per week, one on Tuesdays DS4 (13.00-14.30) and Wednesdays DS4 (13.00-14.30). We're currently planning the course sessions as on-site events. If necessary, we can retract to an Online mode, probably using BigBlueButton. Exercises are intertwined with the lecture.
• Aceto, L., Ingólfsdóttir, A., Larsen, K. G., & Srba, J. (2007). Reactive Systems. Cambridge University Press.
• Sangiorgi, D., & Walker, D. (2003). The pi-calculus: a theory of mobile processes. Cambridge University Press.
• Sangiorgi, D. (2012). Introduction to bisimulation and coinduction. Cambridge University Press.
• Milner, R. (1980). A calculus of communicating systems. : Springer Berlin Heidelberg.
• Milner, R. (1999). Communicating and mobile systems. : Cambridge University Press.
• Davide Sangiorgi (2012). Advanced topics in bisimulation and coinduction. : Cambridge University Press.
• Reisig, W. (2013). Understanding Petri Nets. : Springer Berlin Heidelberg.
 Lecture A Primer in Semantics of Programming Languages DS3, April 5, 2022 in APB E005 File No session no lecture DS3, April 6, 2022 in APB E005 Lecture Bisimilarity DS4, April 12, 2022 in APB E005 File Lecture Bisimilarity and Interaction (Part 1) DS4, April 13, 2022 in APB E010 Lecture Bisimilarity and Interaction (Part 2) DS4, April 19, 2022 in APB 3027 Lecture The Calculus of Communicating Systems DS4, April 20, 2022 in APB 3027 File Lecture Expressive Power of CCS DS4, April 26, 2022 in APB 3027 Lecture Algebraic Properties of Bisimilarity DS4, April 27, 2022 in APB E010 Lecture Processes with Internal Steps DS4, May 3, 2022 in APB 3027 File Lecture Algebraic Properties of Weak Bisimilarity DS4, May 4, 2022 in APB E010 Lecture CCS, Bisimilarity Conclusions / Introduction to Petri Nets DS4, May 10, 2022 in APB 3027 File Lecture Petri Nets and CCS DS4, May 11, 2022 in APB E010 Lecture Petri Nets: Algorithms DS4, May 17, 2022 in APB 3027 No session Dies academicus DS4, May 18, 2022 in APB E010 Lecture Petri Nets: Expressiveness DS4, May 24, 2022 in APB 3027 File Lecture Petri Nets: Non-Interleaving Semantics (Part 1) DS4, May 25, 2022 in APB E010 Lecture Petri Nets: Non-Interleaving Semantics (Part 2) DS4, May 31, 2022 in APB 3027 Consultation Questions and Answers (Petri Nets, CCS, and LTS) DS4, June 1, 2022 in APB E010 No session Pentecost Week DS4, June 7, 2022 in APB 3027 No session Pentecost Week DS4, June 8, 2022 in APB E010 Lecture Reductions DS4, June 14, 2022 in APB 3027 Lecture Barbed Congruence DS4, June 15, 2022 in APB E010 Lecture The Pi-Calculus: Syntax and Reduction Semantics DS4, June 21, 2022 in APB 3027 File Lecture The Pi-Calculus: Examples and Reductions DS4, June 22, 2022 in APB E010 Lecture The Pi-Calculus: Labeled Transition Semantics DS4, June 28, 2022 in APB 3027 Lecture The Pi-Calculus: Properties of the LTS-Semantics DS4, June 29, 2022 in APB E010 Lecture The Pi-Calculus: The Harmony Lemma DS4, July 5, 2022 in APB 3027 Lecture The Asynchronous Pi-Calculus DS4, July 6, 2022 in APB E010 Lecture Relative Expressive Power DS4, July 12, 2022 in APB 3027 Lecture Wrap-Up DS4, July 13, 2022 in APB E010