It doesn't explain the grammar in detail. Of course, it would be too much to explain one by one, but even considering that, the explanation of the functions is severely lacking. This is not like the lecture where you write down a function when you come across a function you've never seen before and run a simulator, but rather, the lectures that get longer write down a bunch of functions you've never seen before and then run a simulation once at the end to show the results and that's it. In this case, you have to guess which function does what by feeling or comment out each function, run a simulation, comment out each function, and run a simulation to check. Even then, if you don't know what structure the function is in, you have to Google it, but there's not enough information on Google and it's all in English, so it's hard. The biggest problem is that they don't even answer questions. Shouldn't they just make a lecture, throw it out there, and ignore it? It's not a free lecture, and they're selling it for money.