I wouldn't say it's necessarily neither. While the concept of binding used in [3] is consistent, you can also simply say that functions are call-by-value and al

I wouldn't say it's necessarily neither. While the concept of binding used in [3] is consistent, you can also simply say that functions are call-by-value and all values are references. Pretty much the same way C uses pointers when passed to a function. BTW, I didn't like the way the difference between mutable and immutable objects was pointed out, it sounded like the language recognized and supported those two types, when in fact the difference is just in the methods exposed by the objects. Even immutable objects can be modified if you don't respect the contracts (like in the case of this article).