Using the Bounded Comprehension Principle, show that if x and y are sets then

so are:

a. $\displaystyle \{z:\forall w( w\epsilon z \rightarrow w\epsilon x) \}$

b. $\displaystyle \{w:\exists z( z\epsilon x \wedge w= y\cap z) \} $

c. $\displaystyle \{w:\exists z( z\epsilon x \wedge w= y\cup z) \} $

I'm just not sure the Bounded Comprehension Principle applies here... could someone explain this?