pyspect: An Extensible Toolbox for Automatic Construction of Temporal Logic Trees via Reachability Analysis

In this paper, we present pyspect, a Python toolbox that simplifies the use of reachability analysis for temporal logic problems. Currently, satisfying complex requirements in cyber-physical systems requires significant manual effort and domain expertise to develop the underlying reachability programs. This high development effort limits the broader adoption of reachability analysis for complex verification problems. To address this, pyspect provides a method-agnostic approach to performing reachability analysis for verifying a temporal logic specification via temporal logic trees (TLTs). It enables the specification of complex safety and liveness requirements using high-level logic formulations that are independent of any particular reachability technique or set representation. As a result, pyspect allows for the comparison of different reachability implementations, such as Hamilton-Jacobi and Hybrid Zonotope-based reachability analysis, for the same temporal logic specification. This design separates the concerns of implementation developers (who develop numerical procedures for reachability) and end-users (who write specifications). Through a simple vehicle example, we demonstrate how pyspect simplifies the synthesis of reachability programs, promotes specification reusability, and facilitates side-by-side comparisons of reachability techniques for complex tasks.