I think "useful" is doing a lot of work here. A lot of math notation exists clearly to gate keep. It's often nonsensical. It's a shame because it really makes mathematicians look bad (re:annoying) to those who can see through it. It's not hard to see through it or anything, but it is obnoxious. All you need is an english explanation of the notation, and then you're good, but often all of the sources on the topic are written in the same obnoxious babble language.

Take sequential Monte Carlo / sequential importance sampling for instance. This powerpoint on it is clownishly bad: http://people.eecs.berkeley.edu/~jordan/courses/260-spring10...

This is supposed to be an algorithm implemented in code. It's essentially illegible without code examples, which it doesn't feature. Code examples tell you what the cipher signifies; at no point does the cipher provide any value to the learner. Fanciful bayes-theoretical statements and so on basically reduce to "iteratively build enlarging valid states." Given the fact that this simple statement is missing, I question if the professor has some sort of communication disorder or if they're just a troll. Similar to pomo philosophers, it's probably a mix.