TIL. I had tried to understand it a bit, but felt lost pretty fast, and then eventually found out that's because it's huge. Is there a good intro to the basic instructions you're aware of?

By "play act the compiler" I mean a fairly elaborate system of written notes that significantly exceeds the size of the actual program. Like, it's no wonder they started thinking about building machine compilers at that stage.

What language is your pseudocode example modeled after? It vaguely reminds me of some iOs App code I helped debug (Swift?) but I never really learned the language so much as eyeballed it with educated guesses, and even with the few things I double checked it has been a few years, so I have no clue what is or isn't legal syntax anymore.