nperkins7 at home.com
Mon Jun 4 22:48:42 CEST 2001
You are right, and I promise not to try to do logic after 4 in the morning.
My own truth table clearly shows that B implies that P is true.
( and that D is false )
I am the one who was confused, when I drew my conclusion.
( goes to show why explicit logical reasoning is better than statements in
english -- no argument is necessary! )
"Alex Martelli" <aleaxit at yahoo.com> wrote in message
news:9fflob32q4r at enews2.newsguy.com...
> "Nick Perkins" <nperkins7 at home.com> wrote in message
> news:V7xS6.126372$eK2.29676821 at news4.rdc1.on.home.com...
> > A: (P implies (not D))
> > "Given a powerful army, I could not defeat Napolean"
> > B: (not (P implies D))
> > "Having a powerful army would not ensure that I could..."
> > truth table:
> > P D A:(P implies (not D)) B:(not (P implies D))
> > 0 0 1 0
> > 0 1 1 0
> > 1 0 1 1
> > 1 1 0 0
> > The difference is that statement A is true if P is false,
> > whereas statement B can only be true if P is true.
> > Therefore, statement B implies that P is false.
> I think I'm getting confused. From the truth table above,
> AND for the immediately preceding statement, I would
> deduce the _opposite_ conclusion than yours, i.e., "B
> implies that P is _true_". How do you get the "implies
> that P is _false_" instead?
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