It's very similar. There are major differences with how functions are typed, however. Namely, in Cat, they are, and in this, they are not. There's a good reason for that, though!

Imagine you write the program "(add print) call". Clearly that function takes two integer arguments. Right?

Well, that's only because you're looking at the high-level version. Compile it down and you get AE 1D B0 88. If you run it on two integers, you get the sum, as expected.

But what happens if you run it with a list on the stack? Then it happens to run the program "(arg-min arg-a) call". Why? The arithmetic-decoder just sees some bytes, and it decodes them to match the correct types.

Representing the actual type of functions would require more bits, make programs longer, and so I haven't implemented that. I'm still pondering things to do here.