Diagramming either/or

[redcobra21]

Hey!

I was wondering if someone could let me know what page in the Manhattan LR or LG strategy guides (I have the full set of Manhattan books, so whatever page is relevant really...) talks about diagramming the conditional logic for either/or statements. I think I went over it but can't recall the exact page right now.

If the rule is: "Either John or Ap attend, but not both", should it be diagrammed: J --> ~A; A --> ~J. And this mean that John or Ap must attend, right? Or would this be a biconditional?

And if the rule is just: "Either John or Ap attend," should it be diagrammed: ~J --> A, ~A --> J.

Thanks!

[tommywallach]

Hey Red,

I don't know what page it's on. The book ain't that big; you can find it! : )

As for how to diagram "Either John or Ap attend, but not both" you do like this:

~J <--> A
~A <--> J

Notice that this forces the issue. If there's no J, there' gotta be A. If there's A, there can't be J. If there's no A, there's gotta be J. If there's J, there can't be A.

For "Either John or Ap attend," you nailed the weird LSATness that "either/or" means you could have both of them attend. So it would look just like you wrote:

~J --> A
~A --> J

This forces you to have at least one of them, but there's no reason you can't have both.

Hope that helps!

-t