I do not know what you mean by and . Can you explain yourself?Originally Posted byerinthered

Let me try it like this:

1) (function)

2) (subset)

3)Then,

4)Thus,

Because, since we have because this function maps an element from A into B. But, implies thus, for all we have, . Thus, for all we have thus,

But I do not know if you were asking this?