Oog.

[logomancer]

Just came back from Discrete Math. Brown was in rare form today, as he explained to us the mechanics of conditional statements. My biggest beef with the class is this: It claims to be a class to teach reasoning skills, but the concepts he presents sometimes are not logical. For example, we learned about the conditional statement, "p implies q". p is what we called a hypothesis and q is a conclusion. However, Brown tells us that if p is false and q is true, then the conditional statement is true. Which puts me off because if one's hypothesis is false, how can one derive a conclusion that is true? And even if that's the case, how does that prove that the conditional statement is true? It's confusing.

The rest of the class was somewhat easier to follow. Nothing compared to Chemistry, where Prof. Amateis played with liquid nitrogen today, freezing a banana and breaking it (although it didn't shatter -- it wasn't cold enough). She also splashed some LN₂ on the floor, which freaked out the first row ("Oh, and by the way, class, be sure to wear closed-toe shoes in your labs.") Very cool.

Anyway, I need folders, dinner, and Spiel.

Comments

[slitherrr.livejournal.com]

here's another thing. assume p -> q. like those guys up there said a million times, if p is true, then the entire statement p -> q is true. q is not necessarily true, and is not necessarily false. it's just that p -> q as a statement is still valid, because it has not been proven to be false.

for example: assuming the statement "'Ed is a dog" implies "Ed has four legs'" is true:
if Ed is, indeed, a dog, then he has four legs
if Ed is not a dog, then he may or may not have four legs, but since you haven't proven the implication false, it is still true, since you have not proven that there exists an Ed that is a dog but does not have four legs.

my main point is, you're saying "if one's hypothesis is false, how can one derive a conclusion that is true?", and you're way off base. your hypothesis, that Ed is a dog, isn't saying that your conclusion, that Ed has four legs, is correct if Ed isn't a dog. it's just saying that, as a statement, "Ed is a dog implies Ed has four legs" is still valid, and makes no comment whatsoever on whether or not Ed the non-dog, indeed, has four legs.