Specification and Verification of a Formal Model for a Real-Time System Using TLA+

The paper describes theoretical and applied aspects of modeling real-time information systems using the example of a continuous glucose monitoring (CGM) system. The primary focus is on the application of formal methods, in particular the TLA+ specification language and modal logics, which ensure mathematical precision in describing system behavior. A formal model of the CGM system is constructed, safety invariants are defined, and automated model verification is performed using the TLC mechanism. The obtained results can be used to improve the reliability and justify the correctness of software-hardware solutions in the field of medical IT systems, particularly Closed-Loop Systems (CLS), which currently lack appropriate regulatory certification. The proposed approach contributes to the formalization of the validation process for such systems in accordance with standards for safety-critical software.