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Re: P ∨ Q, ¬P Q
Posted: Thu Oct 27, 2011 4:27 pm
by Maureen K Clifford
you think?????
If I am the axe murderer, then I used an axe.
If I used a chainsaw to cut up and hack
I would be a chainsaw murderer or worse
I could kill off my victims with my poison verse.
I cannot use an axe. Therefore logically I am not the axe murderer.
Re: P ∨ Q, ¬P Q
Posted: Thu Oct 27, 2011 4:35 pm
by Stephen Whiteside
Brain fever,
modus tollens.
Hayfever,
modus pollens.
Re: P ∨ Q, ¬P Q
Posted: Thu Oct 27, 2011 5:01 pm
by manfredvijars
... the equivelant in first-order predicate logic:
\forall x.~P(x) \to Q(x)
\exists x.~\neg Q(x)
\therefore \exists x.~\neg P(x)
Re: P ∨ Q, ¬P Q
Posted: Wed Nov 02, 2011 11:48 pm
by Dave Smith
Oh Right!
Re: P ∨ Q, ¬P Q
Posted: Thu Nov 03, 2011 5:33 am
by Zondrae
you've lost me.
Re: P ∨ Q, ¬P Q
Posted: Thu Nov 03, 2011 5:53 am
by Bob Pacey
Today I will either play golf
Or I will mow the yard.
I will not play golf
Therefore I will mow the yard.
Robert
Re: P ∨ Q, ¬P Q
Posted: Thu Nov 03, 2011 6:56 am
by Kym
Uh huh ...
All I understood in the above, is that someone is having ice cream and it's not me!
Re: P ∨ Q, ¬P Q
Posted: Fri Nov 04, 2011 12:25 am
by Glenny Palmer
......
............
Nothing is heavier than an elephant.
A feather is heavier than nothing.
Therefore...a feather is heavier than an elephant.........
Re: P ∨ Q, ¬P Q
Posted: Fri Nov 04, 2011 5:17 am
by Kym
Ooohhhh, good one Glenny!!!!!
Gold star for you m'lady.
Re: P ∨ Q, ¬P Q
Posted: Fri Nov 04, 2011 7:39 am
by Maureen K Clifford