The 15th International Conference on Reachability Problems (RP'21) is being organised by the Department of Computer Science at the University of Liverpool.

Papers presenting original contributions related to reachability problems in different computational models and systems are being sought. This will also be the occasion to review recent breakthroughs by renowned invited experts and survey emerging trends and emphasise on key open challenges. Participants are kindly encouraged to discuss core scientific issues that need to be further tackled.

The conference proceedings will be published in Springer's Lecture Notes in Computer Science (LNCS). A selection of articles among the contributed papers will be invited to a special issue of a journal (TBA).


The conference is specifically aimed at gathering together scholars from diverse disciplines and backgrounds interested in reachability problems that appear in

  • ●  Algebraic structures
  • ●  Automata theory and formal languages
  • ●  Computational game theory
  • ●  Concurrency and distributed computation
  • ●  Decision procedures in computational models
  • ●  Hybrid dynamical systems
  • ●  Logic and model checking
  • ●  Verification of finite and infinite-state systems

Topics of interest include (but are not limited to): reachability problems in infinite-state systems, rewriting systems, dynamical and hybrid systems; reachability problems in logic and verification; reachability analysis in different computational models, counter timed/ cellular/ communicating automata; Petri nets; computational and combinatorial aspects of algebraic structures (semigroups, groups and rings); frontiers between decidable and undecidable reachability problems; predictability in iterative maps and new computational paradigms.

Venue & COVID-19

The intention is to hold the conference in Liverpool if possible, or else to host it virtually, depending on the COVID-19 situation. We will continue to monitor the global travel situation, and update this section once a final decision has been made.

Anti-Harassment Policy

We believe that the advancement of research is best accomplished in an environment that is open, diverse and respectful to all participants. During the conference, we will follow the anti-harassment policy of ACM. Anyone witnessing or subject to unacceptable behaviour should notify the conference chairs.