@JaceGuinto95 to be clear, if by the arrow “->” we mean “logically necessitates”, then a->b does not imply b->a. But if we mean “increases the likelihood of” then yes. But then this wouldn’t imply that a and b are the same, just that they have some mutual information.

@DanielCullis What I mean is that the definition of "support" in the context of the LSAT is "increasing likelihood", i.e., increasing probability. But it is a mathematical fact that if A increases the probability of B then B must also increase the probability of A.

But are you saying the asymmetry comes from the arguer's intention?

I'm confused about our application of the definition of "support".

We said A supports B iff A increases the likelihood of B. But in probability theory, this relation is always symmetric: if A supports B, then B supports A (by the same ratio, according to Bayes' theorem).

In the tiger example, the conclusion does actually support the premise: to see this, note that if all mammals were suitable pets, it would be pretty unlikely for tigers to be maiming humans.

So I'm wondering how to reconcile this with the directional arrows between premise and conclusion, the different words used, etc.

I'm confused about our application of the definition of "support".

We said A supports B iff A increases the likelihood of B. But in probability theory, this relation is always symmetric: if A supports B, then B supports A (by the same ratio, according to Bayes' theorem).

In the tiger example, the conclusion does actually support the premise: to see this, note that if all mammals were suitable pets, it would be pretty unlikely for tigers to be maiming humans.

So I'm wondering how to reconcile this with the directional arrows between premise and conclusion, the different words used, etc.

I'm confused about our application of the definition of "support".

We said A supports B iff A increases the likelihood of B. But in probability theory, this relation is always symmetric: if A supports B, then B supports A (by the same ratio, according to Bayes' theorem).

In the tiger example, the conclusion does actually support the premise: to see this, note that if all mammals were suitable pets, it would be pretty unlikely for tigers to be maiming humans.

So I'm wondering how to reconcile this with the directional arrows between premise and conclusion, the different words used, etc.