Whether $x^{y^{z}}$ should be considered as $x^{\left ( y^{z} \right )}$ or $\left ( x^{y} \right )^{z}$, without any context?
If any one among these two is default consideration?
$\left ( x^{y} \right )^{z}$ appears more natural to me, but my calculator does it other way.
The usual convention is $x^{y^z} = x^{(y^z)}$ because if you want $(x^y)^z$ the equivalent expression $x^{yz}$ is simpler (no parenthesis required).