Verification of fault tolerance and real time

A transformational method is given for specifying and verifying fault-tolerant, real-time programs. Such a program needs to be provably correct according to both its functional and real-time requirements, despite the possible occurrence of system failures. The paper demonstrates that a suitably expressive logic for real-time systems makes it possible to naturally model the state changes caused by system failures and determine their effect on the functional and real-time properties of executions.