Solving decision problems using parameterised Boolean equation systems In the mCRL2 toolset, model checking problems are solved by first encoding them into parameterised Boolean equation systems (PBES) and then finding the solution to this PBES. However, PBESs are very expressive and can be used to encode more types of decision problems. For example, one can also encode equivalence problems and scheduling problems in the framework of PBESs. The goal of this assignment is to further investigate the expressiveness of PBESs. Possible directions are: defining an encoding of the longest common substring problem in PBES [1] or encoding PBESs that express whether a certain mu-calculus formula is satisfiable [2], i.e., whether there is a model that satisfies the formula. Inspiration can also be drawn from common problems in the SAT/SMT-solving world. [1]: Hutagalung M., Lange M. (2014) Model Checking for String Problems. In: Hirsch E.A., Kuznetsov S.O., Pin J.E., Vereshchagin N.K. (eds) Computer Science - Theory and Applications. CSR 2014. Lecture Notes in Computer Science, vol 8476. Springer. [2]: Friedmann, Oliver and Lange, Martin and Latte, Markus - Satisfiability Games for Branching-Time Logics, lmcs:761 - Logical Methods in Computer Science, October 16, 2013, Volume 9, Issue 4.