The transitional frequency matrix

The most basic question scientists ask about a dynamics is: when event $a$ happens, what usually happens next? ^3.1 Another event $b$ or $c$? the same event $a$? This is the very essence of a process. A phenomenon that changes over time. What we want to determine is what event usually follows another event. But let's first see how a sequence of events may be described in a more compact fashion.