[sixfiveotwo]

> I think a memory address is a number that CPU considers to be a memory address

I meant to say that, indeed, there must be some concept of CPU for a memory address to have a meaning, and for this concept of CPU to be as widely applicable as possible, surely defining it as abstract as possible is the way to go. Ergo, the idea of a C abstract machine.

Anyway, other people in this thread are discussing the matter more accurately and in more details than I could hope to do, so I'll leave it like that.