BmcMT: Bounded Model Checking of TLA + Specifications with SMT

Igor Konnov (1, 2) , Jure Kukovec (3) , Thanh Hai Tran (3)

1 VERIDIS - Modeling and Verification of Distributed Algorithms and Systems
2 MOSEL - Proof-oriented development of computer-based systems
3 TU Wien - Vienna University of Technology = Technische Universität Wien

We present the development version of BmcMT—a symbolic model checker for TLA+. It finds, whether a TLA+ specification satisfies an invariant candidate by checking satisfiability of an SMT formula that encodes: (1) an execution of bounded length, and (2) preservation of the invariant candidate in every state of the execution. Our tool is still in the experimental phase, due to a number of challenges posed by TLA+ semantics to SMT solvers. We will discuss these challenges and our current approach to them in the talk. Our preliminary experiments show that BmcMT scales better than the standard TLA+ model checker TLC for large parameter values, e.g., when a TLA+ specification models a system of 10 processes, though TLC is more efficient for tiny parameters, e.g., when the system has 3 processes. We believe that early feedback from the TLA+ community will help us to focus on the most important language features and improve our tool.

Domaines: Génie logiciel [cs.SE]; Logique en informatique [cs.LO]

Igor Konnov, Jure Kukovec, Thanh Hai Tran. BmcMT: Bounded Model Checking of TLA + Specifications with SMT. TLA+ Community Meeting 2018, Jul 2018, Oxford, United Kingdom. ⟨hal-01899719⟩