I am Professor of Trustworthy Software Technologies at Taltech. The position is a research measure of the IT Academy programme, funded by the Estonian State and the European Social Fund. I lead the Laboratory for Compositional Systems and Methods. In 202125 I am also PI of the Estonian Research Council grant PRG1210,
Automata in Learning, Interaction and Concurrency (ALICE).
My research can be understood as the study of how to connect open systems (of various kinds: programs, networks, computing devices, circuits, ...) in a way that the description of the connectionsi.e. the language that we describe subsystems and how to compose themis compatible with the behaviour of the system. Therefore, what can be observed of the global system is entirely derivable from the observations made of the component subsystems. This is because each composition operation in the language we use for describing systems gives rise to an analogous operation on the behaviours. This property is known as compositionality.
I focus on compositional modelling of systems, developing the underlying mathematics (usually category theory), and applying it to reallife problems such as verification. I work on graph transformation, Petri nets, process algebras, dynamical and cyberphysical systems, as well as mainstream concurrent programming.
Since 2015, I write the Graphical Linear Algebra blog about rediscovering linear algebra in a compositional way, with string diagrams.
 Upcoming meetings

 Recent meetings

 Organisations

 Programme committees

2023
 38th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2023)
 16th International Conference on Graph Transformation (ICGT 2023)
2022
2021
2020
2019
 PhD students

201115  Owen Stephens, Compositional Specification and Reachability Checking of Net Systems, ECS, University of Southampton, with Julian Rathke

201215  Fabio Zanasi, Interacting Hopf Algebras: the Theory of Linear Systems, Ecole Normale Supérieure Lyon, with Filippo Bonchi

201620  Jens Seeber, IMT School for Advanced Studies Lucca, Logical Completeness for String Diagrams, IMT School for Advances Studies, Lucca, with Filippo Bonchi 
2018  Paul Wilson, ECS, with Fabio Zanasi 
2019  Nathan Haydon, TTU 
2019  Chad Nester, TTU 
2019  Elena di Lavore, TTU 
2019  Mario Román, TTU 
2020  Matt Earnshaw, TTU 
2020  Diana Kessler, TTU, with Amar Hadzihasanovic 
 Publications

 João Paixão, Lucas Rufino and Paweł Sobociński, "Highlevel axioms for graphical linear algebra", In Science of Computer Programming, vol. 218, pp. 102791, 2022.
 Filippo Bonchi and Fabio Gadducci and Aleks Kissinger and Pawel Sobocinski and Fabio Zanasi, "String Diagram Rewrite Theory I: Rewriting with Frobenius Structure", In J. ACM, vol. 69, no. 2, pp. 14:1–14:58, 2022.
 Ivan Di Liberti, Fosco Loregian, Chad Nester and Pawel Sobocinski, "Functorial Semantics for Partial Theories", In 48th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2021), 2021.
 Elena Di Lavore, Jules Hedges and Pawel Sobocinski, "Compositional modelling of network games", In 29th EACSL Annual Conference on Computer Science Logic (CSL 2021), 2021.
 Filippo Bonchi and Pawel Sobocinski and Fabio Zanasi, "A Survey of Compositional Signal Flow Theory", Chapter in Advancing Research in Information and Communication Technology  IFIP's Exciting First 60+ Years, Views from the Technical Committees and Working Groups (Michael Goedicke, Erich J. Neuhold, Kai Rannenberg, eds.), Springer, vol. 600, pp. 29–56, 2021.
 Filippo Bonchi and Robin Piedeleu and Pawel Sobocinski and Fabio Zanasi, "Bialgebraic foundations for the operational semantics of string diagrams", In Inf. Comput., vol. 281, pp. 104767, 2021.
 Filippo Bonchi and Alessandro Di Giorgio and Pawel Sobocinski, "Diagrammatic Polyhedral Algebra", In 41st IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2021, December 1517, 2021, Virtual Conference (Mikolaj Bojanczyk, Chandra Chekuri, eds.), Schloss Dagstuhl  LeibnizZentrum für Informatik, vol. 213, pp. 40:1–40:18, 2021.
 , "A Canonical Algebra of Open Transition Systems", In Formal Aspects of Component Software  17th International Conference, FACS 2021, Virtual Event, October 2829, 2021, Proceedings (Gwen Salaün, Anton Wijs, eds.), Springer, vol. 13077, pp. 63–81, 2021.
 Filippo Bonchi and Alessio Santamaria and Jens Seeber and Pawel Sobocinski, "On Doctrines and Cartesian Bicategories", In 9th Conference on Algebra and Coalgebra in Computer Science, CALCO 2021, August 31 to September 3, 2021, Salzburg, Austria (Fabio Gadducci, Alexandra Silva, eds.), Schloss Dagstuhl  LeibnizZentrum für Informatik, vol. 211, pp. 10:1–10:17, 2021.
 Joao De Paixao and Pawel Sobocinski, "Calculational Proofs in Relational Graphical Linear Algebra", In 23rd Brazilian Symposium on Formal Methods (SBMF 2020), 2020.
 Nathan Haydon and Pawel Sobocinski, "Compositional Diagrammatic FirstOrder Logic", In 11th International Conference on the Theory and Application of Diagrams (DIAGRAMS 2020), 2020.
 Nicolas Behr and Pawel Sobocinski, "Rule Algebras for Adhesive Categories", In Log. Methods Comput. Sci., vol. 16, no. 3, 2020.
 Filippo Bonchi and Robin Piedeleu and Pawel Sobocinski and Fabio Zanasi, "Contextual Equivalence for Signal Flow Graphs", In 23rd International Conference on Foundations of Software Science and Computation Structures (FoSSaCS 2020), Springer, vol. 12077, pp. 77–96, 2020.
 Paweł Sobociński, Paul Wilson and Fabio Zanasi, "CARTOGRAPHER: a tool for string diagrammatic reasoning", In 8th Conference on Algebra and Coalgebra in Computer Science (CALCO 2019), 2019.
 Filippo Bonchi, Robin Piedeleu, Paweł Sobociński and Fabio Zanasi, "Bialgebraic Semantics for String Diagrams", In 30th International Conference on Concurrency Theory, (CONCUR 2019), pp. 37:1–37:17, 2019.
 Filippo Bonchi, Jens Seeber and Paweł Sobociński, "The Axiom of Choice in Cartesian Bicategories", In 8th Conference on Algebra and Coalgebra in Computer Science (CALCO 2019), 2019.
 Filippo Bonchi, Robin Piedeleu, Paweł Sobociński and Fabio Zanasi, "Graphical Affine Algebra", In ACM/IEEE Symposium on Logic and Computer Science (LiCS `19), 2019.
 Filippo Bonchi, Joshua Holland, Robin Piedeleu, Paweł Sobociński and Fabio Zanasi, "Diagrammatic Algebra: From Linear to Concurrent Systems", In 46th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2019), 2019.
 Apiwat Chantawibul and Paweł Sobociński, "Monoidal multiplexing", In 15th International Colloqium on Theoretical Aspects of Computing, 2018.
 Filippo Bonchi, Fabio Gadducci, Aleks Kissinger, Paweł Sobociński and Fabio Zanasi, "Rewriting with Frobenius", In Proceedings of the 33rd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2018), Oxford, UK, July 0912, 2018, pp. 165–174, 2018.
 Filippo Bonchi, Jens Seeber and Paweł Sobociński, "Graphical Conjunctive Queries", In Computer Science Logic 2018 (CSL 2018), 2018.
 Nicolas Behr and Paweł Sobociński, "Rule Algebras for Adhesive Categories", In Computer Science Logic 2018 (CSL 2018), 2018.
 Filippo Bonchi, Dusko Pavlovic and Paweł Sobociński, "Functorial Semantics for Relational Theories", In arXiv preprint arXiv:1711.08699, 2017.
 Filippo Bonchi, Joshua Holland, Dusko Pavlovic and Paweł Sobociński, "Refinement for signal flow graphs", In Concurrency Theory  28th International Conference, (CONCUR 2017), 2017.
 Filippo Bonchi, Fabio Gadducci, Aleks Kissinger, Paweł Sobociński and Fabio Zanasi, "Confluence of Graph Rewriting with Interfaces", In European Symposium on Programming (ESOP 2017), 2017.
 B. Fong, P. Rapisarda and P. Sobociński, "A categorical approach to open and interconnected dynamical systems", In Thirtyfirst annual ACM/IEEE symposium on Logic and Computer Science (LICS `16), 2016.
 F. Bonchi, P. Sobociński and F. Zanasi, "Lawvere theories as composed PROPs", In 13th International Workshop on Coalgebraic Methods in Computer Science (CMCS `16), 2016.
 F. Bonchi, F. Gadducci, A. Kissinger, P. Sobociński and F. Zanasi, "Rewriting modulo symmetric monoidal structure", In Thirtyfirst annual ACM/IEEE symposium on Logic and Computer Science (LICS `16), 2016.
 A. Chantawibul and P. Sobociński, "Towards Compositional Graph Theory", In MFPS XXXI, 2015.
 F. Bonchi, P. Sobociński and F. Zanasi, "The Calculus of Signal Flow Diagrams I: Linear Relations on Streams", 2015.
 F. Bonchi, P. Sobociński and F. Zanasi, "Full Abstraction for Signal Flow Graphs", In Principles of Programming Languages, POPL`15., 2015.
 P. Sobociński and O. Stephens, "A Programming Language for Spatial Distribution of Net Systems", In Petri Nets `14, 2014.
 J. Rathke, P. Sobociński and O. Stephens, "Compositional Reachability in Petri Nets", In Reachability Problems, 2014.
 V. Danos, R. Heckel and P. Sobociński, "Transformation and Refinement of Rigid Structures", In ICGT`14, 2014.
 F. Bonchi, P. Sobociński and F. Zanasi, "A Categorical Semantics of Signal Flow Graphs", In CONCUR`14, 2014.
 F. Bonchi, P. Sobociński and F. Zanasi, "Interacting Hopf Algebras", Technical report, arXiv:1403.7048, 2014.
 F. Bonchi, P. Sobociński and F. Zanasi, "Interacting Bialgebras are Frobenius", In FoSSaCS `14, 2014.
 J. Rathke, P. Sobociński and O. Stephens, "Decomposing Petri nets", 2013.
 P. Sobociński, "Relational Presheaves, Change of Base and Weak Simulation", In JCSS, 2013.
 P. Sobociński, "Nets, relations and linking diagrams", In Algebra and Coalgebra in Computer Science (CALCO `13), 2013.
 P. Sobociński and O. Stephens, "Reachability via compositionality in Petri nets", 2013.
 R. Bruni, H.C. Melgratti, Ugo Montanari and P. Sobociński, "Connector Algebras for C/E and P/T Nets' Interactions", In Log. Meth. Comput. Sci., 2013.
 P. Sobociński, "Relational presheaves as labelled transition systems", In Coalgebraic Methods in Computer Science (CMCS `12), Springer, vol. 7399, pp. 4050, 2012.
 P. Baldan, A. Corradini, T. Heindel, B. König and P. Sobociński, "Processes and Unfoldings: Concurrent Computations in Adhesive Categories", 2012.
 J. Lantair and P. Sobociński, "WiCcA: LTS generation tool for wire calculus", In Algebra and Coalgebra in Computer Science (CALCO Tools `11), Springer, vol. 6859, pp. 407–412, 2011.
 T. Heindel and P. Sobociński, "Being Van Kampen is a universal property", In Log. Meth. Comput. Sci., vol. 7, no. 1, 2011.
 P. Baldan, F. Gadducci and P. Sobociński, "Adhesivitiy is not enough: Local ChurchRosser revisited", In Mathematical Foundations of Computer Science (MFCS `11), Springer, vol. 6907, pp. 48–59, 2011.
 P. Sobociński, "Representations of Petri net interactions", In Concurrency Theory (CONCUR `10), Springer, no. 6269, pp. 554–568, 2010.
 J. Rathke and P. Sobociński, "Deriving structural labelled transitions for mobile ambients", In Information and Computation, vol. 208, pp. 12211242, 2010.
 P. Sobociński, "A noninterleaving process calculus for multiparty synchronisation", In ICE '09, 2009.
 J. Rathke and P. Sobociński, "Making the unobservable, unobservable", In Proceedings of ICE '08, vol. 229, no. 3, pp. 131–144, 2009.
 T. Heindel and P. Sobociński, "Van Kampen colimits as bicolimits in Span", In Algebra and Coalgebra in Computer Science (Calco '09), Springer, no. 5728, pp. 335–349, 2009.
 M. Carbone, P. Sobociński and F. D. Valencia, "Foreword: Festschrift for Mogens Nielsen's 60th birthday", In Theor. Comput. Sci., vol. 410, no. 41, pp. 4001–4005, 2009.
 P. Baldan, A. Corradini, T. Heindel, B. König and P. Sobociński, "Unfolding grammars in adhesive categories", In Algebra and Coalgebra in Computer Science (Calco '09), Springer, no. 5728, pp. 350–366, 2009.
 A. Corradini, F. Hermann and P. Sobociński, "Subobject transformation systems", In Applied Categorical Structures, Kluwer, vol. 16, no. 3, pp. 389–419, 2008.
 J. Rathke and P. Sobociński, "Deconstructing behavioural theories of mobility", In Fifth IFIP International Conference On Theoretical Computer Science  TCS '08, Springer, 2008.
 J. Rathke and P. Sobociński, "Deriving structural labelled transitions for mobile ambients", In Concurrency Theory (CONCUR `08), Springer, vol. 5201, pp. 462–476, 2008.
 P. Johnstone, S. Lack and P. Sobociński, "Quasitoposes, quasiadhesive categories and Artin glueing", In Algebra and Coalgebra in Computer Science, Calco '07, Springer, vol. 4626, 2007.
 J. Rathke, V. Sassone and P. Sobociński, "Semantic barbs and biorthogonality", In Foundations of Software Science and Computation Structures, FoSSaCS '07, Springer, vol. 4423, pp. 302–316, 2007.
 S. Lack and P. Sobociński, "Toposes are adhesive", In International conference on graph transformation, ICGT '06, Springer, vol. 4178, pp. 184–198, 2006.
 P. Sobociński, "Reversing graph transformations", In Workshop on Petri nets and graph transformations, PNGT '06, vol. 2 (2006), 2006.
 V. Danos, J. Krivine and P. Sobociński, "General reversibility", In International Workshop on Expressiveness in Concurrency, Express '06, Elsevier, 2006.
 P. Baldan, A. Corradini, T. Heindel, B. Koenig and P. Sobociński, "Processes for Adhesive Rewriting Systems", In Foundations of Software Science and Computation Structures, FoSSaCS '06, Springer, vol. 3921, pp. 202–216, 2006.
 V. Sassone and P. Sobociński, "Locating reaction with 2categories", In Theoretical Computer Science, vol. 333, no. 12, pp. 297–327, 2005.
 V. Sassone and P. Sobociński, "A congruence for Petri nets", In Workshop on Petri nets and graph transformation, PNGT '04, Elsevier, vol. 127, pp. 107–120, 2005.
 V. Sassone and P. Sobociński, "Reactive Systems over Cospans", In Logic in Computer Science, LiCS '05, IEEE Press, pp. 311–320, 2005.
 R. Bruni, F. Gadducci, U. Montanari and P. Sobociński, "Deriving weak bisimulation congruences from reduction systems", In International Conference on Concurrency Theory, Concur '05, Springer, vol. 3653, pp. 293–307, 2005.
 B. Klin, V. Sassone and P. Sobociński, "Labels from reductions: towards a general theory", In Algebra and Coalgebra in Computer Science, Calco '05, Springer, vol. 3629, pp. 30–50, 2005.
 S. Lack and P. Sobociński, "Adhesive and quasiadhesive categories", In RAIRO  Theoretical Informatics and Applications, EDP Sciences, vol. 39, no. 2, pp. 522–546, 2005.
 P. Sobociński, "Deriving process congruences from reaction rules", PhD thesis, BRICS, University of Aarhus, 2004.
 P. Sobociński, "Process congruences from reaction rules (Luca Aceto's Concurrency Column)", In Bulletin of the EATCS, vol. 84, 2004.
 P. Sobociński, "Adhesivity, bigraphs and bisimulation congruence", In Dagstuhl Seminar 04241, Graph Transformations and Process Algebras for Modeling Distributed and Mobile Systems, 2004.
 S. Lack and P. Sobociński, "Adhesive categories", In Foundations of Software Science and Computation Structures, FoSSaCS '04, Springer, vol. 2987, pp. 273–288, 2004.
 V. Sassone and P. Sobociński, "Deriving Bisimulation Congruences Using 2categories", In Nordic Journal of Computing, vol. 10, no. 2, pp. 163–183, 2003.
 V. Sassone and P. Sobociński, "Deriving bisimulation congruences: 2categories vs precategories", In Foundations of Software Science and Computation Structures, FoSSaCS '03, Springer, vol. 2620, 2003.
 B. Klin and P. Sobociński, "Syntactic Formats for Free: An Abstract Approach to Process Equivalence", In International Conference on Concurrency Theory, Concur '03, Springer, vol. 2620, pp. 72–86, 2003.
 V. Sassone and P. Sobociński, "Deriving Bisimulation Congruences: A 2categorical Approach", In International Workshop on Expressiveness in Concurrency, Express '02, Elsevier, vol. 68, no. 2, 2002.