Proof the proposition.
For this question. I have no idea how to start.
The P(I) just messes me up.
Since J belongs in the set P(I), shouldn't the statement be ⊆ instead of the top one?
which is all K ∈ I, X∈ Sk
which is all K ∈ J, X∈ Sk
Some hints to get me start the question would be helpful. Thank you.