4 ms·

But since |BP| is both 1 and 2 it means Bertrand Russell is both the Pope, and not the Pope.

• unanswered 6y ago
  ... yes. That is indeed what is meant by ex falso quodlibet. It does not make the example invalid.
  • DangitBobby 6y ago
    The point was merely that it cannot be used to prove "anything" since the actual conclusions do not necessarily follow, leaving the original claim that you can prove anything with false axioms unproven.
    • unanswered 6y ago
      The conclusion "Bertrand Russell is the Pope" does necessarily follow from 1=0. I'm not sure why you think it doesn't. The conclusion "Bertrand Russell is not the Pope" also follows. Yes, this is a contradiction. So is 1=0.
      • DangitBobby 6y ago
        The claim was that if you accept a false premise, you can prove any false thing to be true. What we've actually seen is random claiming of contradictory things that supposedly follow by people trying to appear clever. It so obviously doesn't follow that it's a little strange we are having this conversation. If the conclusions themselves can be seen to be contradictory, anyone can dismantle your proof and show that it's bogus, even if you do accept the original premise. So the claim is bogus, and it's probably not a real story anyway.
        • unanswered 6y ago
          The most wonderful thing about mathematics (and by extension logic) is that we don't have to give a shit what random people like yourself want to guess on the internet. We have actual proof checkers. They can show the correctness of proof terms for exfalso from more basic, more obviously correct principles. Those proof terms can't be "dismantled"; they're proved correct no matter how much you whine that you don't like them.