I would like to know the mathematical implication of the cross symbol. Consider $S$ as set of states and $T$ as the set of events. What would be the mathematical meaning if you have $S \times T \times S $ ?
I read as "Set–stage: Fxr denotes that set x “is formed at” stage r;". I couldn't follow this explanation. Can someone provide a proper reference link or explanation?
I encountered this while analyzing a state transition system.