LogFire

Rule-based systems seem natural for runtime verification (RV)/program monitoring. From a specification notation point of view, rule-based systems appear quite suitable for expressing the kind of properties the runtime verification community normally writes. Specifications written in a rule system have an operational flavor, which can be seen as a disadvantage or an advantage, depending on the viewpoint. The operational flavor makes specifications longer than in declarative temporal logic or regular expressions; however, they are natural to write. Once the core idea is mastered, writing rules is straightforward, like programming. More declarative specifications can be trickier to get right. This observation is similar to the observation that it may be easier to formulate a nontrivial property as a state machine than as a temporal logic formula or a regular expression.