**apologies if this is the wrong part of the forum... it was the closest I could find **
Whilst doing questions in preparation for uni this year, I've been working on some abstract algebra. I was doing pretty well until I came across this:
Prove that
It looks like it should be easy but it's been resisting all attempts that I've tried. I've tried a direct proof that but that didn't go anywhere, nor did a contradiction.
Can anyone please make me look a fool and pull out a solution that is from THE BOOK?
Plato has given a counter example to the theorem, which evidently disproves the theorem. If the question doesn't place constraints stating that all the sets have to be different,
we could try making simpler counter examples revolving around the empty set.
A = B = {1}
C = D = ∅
Then, {1} is a subset of ∅ will obviously be false.