I'm not sure what you find incomprehensible about the first example. The syntax is pretty standard. The only exotic thing is `$`, which is basically just like putting brackets around the rest of the line. Here's the first example roughly translated to Python:
def main():
x = 2
[x] = ["foo"]
y = 3
[y] = ["bar"]
print(x + y)
Seems about the same level of comprehensibility to me. Is there anything in particular you find difficult to understand?
The second example is expanded out and not how a person would normally write it, but if you're familiar with the basic concepts it's using, it shows why it works very clearly; think of it like assembler.