Chapter 1, Problem 7RQ

a) What is the difference between the quantification $\exists x\forall yP\left(x,y\right)$ and $\forall y\exists xP\left(x,y\right)$ , where $P\left(x,y\right)$ is a predicate?

b) Give an example of a predicate $P\left(x,y\right)$ such that $\exists x\forall yP\left(x,y\right)$ and $\forall y\exists xP\left(x,y\right)$ have different truth values.