If $X,Y$ are complexity classes in the polynomial hierarchy with $X\subseteq Y$. With abuse of notation assume $X,Y$ also as the TMs that accept languages in classes $X,Y$ respectively.
Then is it always true $X^Z\subseteq Y^Z$ if $Z$ is another complexity class?
If not what is an easy way and example to understand $X^Z\subseteq Y^Z$ need not be true?
