Sure. Possible sequences of events in a concurrent or distributed system. Model checkers in languages like TLA+ have to contend with this. Of course in the real

Sure. Possible sequences of events in a concurrent or distributed system. Model checkers in languages like TLA+ have to contend with this. Of course in the real world only a single sequence of events actually occurs, but you have to know that your system works on that sequence whatever it is. The AWS TLA+ paper noted that at scale you’re basically guaranteed to eventually hit whatever combination of events blows up your system if such a sequence exists. Murphy’s Law of distributed systems I guess.