Prove: If is a function and { } is a family of subset of A, then .
I not getting family of subsets. How do I start this off. Assume x belongs to the left side???
You are proving that the union of images is equal the image of a union.
Because you are working with images you are using existential operators.
Therefore it is best to prove each is a subset of the other.
If then . Then proceed to show that .
Then reverse the process.