Prompted by another question on this site is this notation clear and unambiguous
$$x^{y^z}$$
One answer there seems to imply the meaning is $$x^{(y^z)}$$
Mathcad seams to agree with this making $2^{3^2} = 2^9 = 512$
On the other hand my Casio calculator iterprets this as
$$(x^y)^z$$
Making $2^{3^2} = (2^3)^2 = 8^2 = 64$
My simple question is either of these interpretations correct or do I need to put the brackets in to clarify as I always would anyway.
The first one is used in mathematics, because $(x^y)^z$ is more simply written $x^{yz}$. The same goes for at least some programming languages (Haskell comes to mind), for the same reason.