Seminar: Compositional Techniques for Synthesis and Verification

General Information:

• Instructor: Anne-Kathrin Schmuck, Rupak Majumdar

• Time: Wednesday, 10am
• Place: KL building G 26 room 111, videocast to SB building E1.5 room 105
• Intended Audience: Master or PhD students from computer science or electrical engineering with a special interest in control/synthesis and verification.
• Grading: The final grade will be based on the paper presentation and participation in class.
• Paper Assignment: Please talk to the instructors for a paper assignment based on your interests.

Abstract:

Large scale Cyber Physical Systems (CPS) consist of software, hardware, and physical components interacting in a non-trivial manner. Different parts of these systems are set up using very different design principles, ranging form correct-by-design controllers for physical systems modeled by continuous differential equations, to communication protocols, to code generated by compilers with various characteristics. Due to this intrinsic variability of components and the size of the overall system, synthesis or verification tools cannot be efficiently applied in a monolithic manner to ensure that CPS are safe and work as intended. As a first step towards compositional synthesis and verification techniques for CPS, this seminar investigates existing compositional techniques in relevant sub-domains of CPS analysis and design. We will discuss state-of-the art compositional techniques including for example controller synthesis for continuous-time systems, reactive synthesis over game graphs, or verification of software.

Organization:

Each week we will discuss one topic, based on a representative paper. One participant or the instructor is leading the discussion by giving some general instructional content for the current topic and then presenting the core principles covered in the paper. After this, an open discussion among all participants on the current paper and on the transferability of those insights to other areas is encouraged.

Preliminary Schedule:

• (1) Wed 18.4., 10am, Coordinated Supervisory Control

  • paper

  • Some background Material on Basics for Supervisory Control Theory (SCT):
    • Course Notes by Jörg Raisch

      • link (parts of the introduction and section 4 are relevant for this seminar)

    • Course Notes of W.M. Wonham (the "father" of SCT)

      • link (sec. 1 and 2 give very detailed preliminaries, section 3 is an introduction to SCT)

    • THE standard textbook on SCT by S. Lafortune and C. Cassandras:

      • link (available through the MPI-SWS library via SpringerLink) (sec. 3 is on SCT)

• (2) Wed 25.4., 10am, Introduction to Reactive Synthesis (RS)

  • Somehow there is no good standard reference for an introduction to RS. Nevertheless, here are some pointers:
    • I personally like the first part of Rüdiger Ehlers PhD Thesis as an introduction to RS:

      • link (part 1)

    • A nice read without too much formalization are also the lecture notes by Bernd Finkbeiner :

      • link

    • There is also a general book on "Automata, Logics, and Infinite Games", by Erich Graedel, Wolfgang Thomas, Thomas Wilke,

      • link (Part I covers topics relevant for this seminar)

    • This paper by Zielonka also gives a general introduction to infinite games

      • link (section 1--6 are sufficient)

• (3) Wed 2.5., 10am, Supervisory Control vs. Reactive Synthesis

  • In this session we will
    • recap some basics of SCT (see session (1)),
    • discuss the connection between SCT and RS established here:

      • link

    • discuss a different connection w.r.t. safety specifications

• (4) Wed 9.5., 10am, Supervisory Control vs. Reactive Synthesis (cond.)

  • We will extend the the discussed connection to omega-languages

• (5) Wed 16.5., 10am, Alternative Treatments of Assumptions in Reactive Synthesis

  • We will discuss the following three papers and their connection to the treatment of assumptions in Supervisory Control

    • Assume-Guarantee Synthesis paper

    • Oblidging Games paper

    • Cooperative Reactive Synthesis paper

• (6) Wed 23.5., no seminar

• (7) Tue 29.5., 1pm, A/G methods for compositional safety verification (Damien presenting)

  • e.g. paper

• (8) Wed 6.6., 10am, Distributed Reactive Synthesis

  • We will discuss the classic setting for distributed reactive synthesispaper

  • We will discuss Zielonka automata as a concept for modeling and specifying distributed controller synthesis

    • paper

• (9) Wed 13.6., 10am, distributed A/G based synthesis (students presenting)

  • We will discuss Assume-Admissible Synthesis paper

• (10) Wed 20.6., 10am, Adapting Contracts in Reactive Synthesis (students presenting)

  • We will discuss this paper paper

• (11) Wed 27.6., 10am, no seminar

• (12) Wed 4.7., 10am, (spare slot, might be filled by splitting over-length sessions into two)