A temporal logic of robustness

This thesis presents a new temporal logic of robustness, called Robust Full Computation Tree Logic (RoCTL*) which adds operators for obligation and robustness to the commonly used Full Computation Tree Logic (CTL*). The RoCTL* logic is for reasoning about how robustly a reactive system can ensure that various goals are met in the face of occasional violations of the norms describing the correct behaviour of the system. Such violations may involve, for example network outages or human error. Whereas logics of reliability typically use probabilities, RoCTL* represents robustness in terms of the number of discrete violations that the system can handle while still ensuring some goal is met. As probabilities are often implementation dependant, RoCTL* may be more suited to reasoning about reactive systems in the abstract than existing logics of reliability.