4 ms·
A => B /= ~B => ~A
by Confusion 15y ago
A => B /= ~B => ~A
- MattyDub 15y agoSorry, maybe I'm misreading your notation, but are you saying that modus tollens isn't a valid argument? http://en.wikipedia.org/wiki/Modus_tollens http://en.wikipedia.org/wiki/Modus_tollens
- pilgrim689 15y agoI think he's using a logical implication notation "|=". as in: A => B logically implies that: ~B => ~A He just decided to use "/=" rather than "|="...so it looks weird...
- MattyDub 15y agoAh, I'd read that as "does not equal", rather than "implies". Thanks pilgrim689.
- groovy2shoes 15y agoActually, if the positive is true, then the contrapositive is also true: http://en.wikipedia.org/wiki/Contrapositive http://en.wikipedia.org/wiki/Contrapositive
- Confusion 15y agoAh, I screwed it up :(. I meant to say A => B /= ~A => ~B to convey the fact that if someone says that all useless things are hobbies, then it doesn't follow that things that aren't useless cannot be hobbies, i.e.: that all hobbies must be useless. But as groovy2shoes and MattyDub pointed out, I did it wrongly. Thanks for the kind interpretation pilgrim689 (and indeed, I could have stated that to make the same point), but I was just wrong.