Either or

[pacer]

I am a bit confused about the variations of "either or" and their meanings

either or - does this mean that both A and B can also be possible and neither A and B also possible

vs. either or but not both - here it is explicitly mentioned that both A and B are not possible. Does this mean that at least one A or B

vs. not C unless either not A or B

Can you please explain the difference in what these terms mean?

Here is what I am thinking but not sure if my understanding is correct

either A or B means only A, only B, both A and B or neither A and B

either A or B but not both means only A, only B, neither A and B

not C unless either not A or B means diagram C -> not A or not B OR not A and B together

Thanks

[Emily Haney-Caron]

Hi pacer,

Great question! Understanding either/or phrasing is definitely critical.
Unfortunately, the meaning of either/or phrasing depends on context, and so I can't give you a definite rule for the examples you gave. Fortunately, PowerScore has a great blog post on demystifying either/or language at http://blog.powerscore.com/lsat/bid/268 ... n-the-LSAT. Let me know if that helps, or if you'd like additional explanation!