typo

[Jared-Prime]

But alongside YARV’s internal stack Ruby also keeps track of your Ruby program’s call stack: which methods called which other methods, functions, blocks, lambdas, etc. In fact, YARV is not just a stack machine – it’s a “double stack machine!” It not only has to track the arguments and return values for it’s own internal instructions; it has to do it for your Ruby arguments and return values as well.

Pat Shaughnessy. Ruby Under a Microscope (Kindle Locations 1079-1082).

Should the first sentence read: "alongside YARV's internal stack YARV also keeps track of your Ruby's program's call stack", or am I misreading?

[patshaughnessy]

I tend to use "YARV" and "Ruby" interchangeably, at least in this chapter. I suppose this could be a bit misleading. Maybe I can rewrite that sentence...?