-=Dark_Angel=-, P.I.10 Sep 2004

Two propositions x any y are equivalent if, and only if, x implies y AND y implies x.

I think it's obvious that B implies A, but not obvious that A implies B. Both hold in my opinion, though I can understand you disagreeing with the latter - since that was your original argument - but to disagree with the former seems a bit odd.

The case of B implies A: If B is true, then B must be possible. So A is true. I don't think there is anything wrong with saying that something which is certain is also possible. Of course it's possible. To say it is possible is a weaker statement than saying it is certain, but it is nonetheless true.