[posterboy]

of course that is some kind of iteration because tail recursion is isomorphic to loops and that N-1 sure looks like a while(--N)

[YeGoblynQueenne]

I'm not sure I know what "isomorphic" means in this context.

For sure, (tail) recursion places a pointer to a function on the stack while a loop is a conditional jump. They're not the same thing. I think the similarity between n-1 and --n is a red herring, here.