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7/27/2012 5:21:10 PM

JoshuaXD
JoshuaXD
Posts: 1
In Logic problems, does a statement like "Neither X nor Y is Z" imply that X is not Y? For instance: "The winner was neither Molly nor the teacher." Obviously from this we know Molly didn't win and the teacher didn't win, but do we also know whether or not Molly could be the teacher?

I'd always thought we CAN'T assume Molly isn't the teacher, because for instance if I say "Bob is neither a tall man nor an Italian." I think I'm clearly not implying anything about the existence or non-existence of any tall Italian men.

However if I say "Bob is neither the tall man nor the Italian." I can see how that might be interpreted as implying the tall man and the Italian are two different people. I wouldn't naturally tend to make that assumption, but I've run into a few puzzles now which require substantial trial-and-error guessing if you don't make that assumption.

So that has me rethinking this...

7/27/2012 5:31:07 PM

Amy Lowenstein
Amy Lowenstein
Posts: 1599
I think you're right that "Bob is neither THE tall man nor THE Italian" means that, among other things, the tall man isn't the Italian. Sometimes a puzzle will mention near its beginning, just such advice (for example, it would say that the phrase "Bob is neither the tall man nor the Italian" means Bob is not the tall man, Bob is not the Italian, and the tall man isn't the Italian).

I always do assume that the phrase "NEITHER x nor y" means x isn't y. Without even going into the next part of the sentence -- the "is Z" part -- but just looking at the first phrase -- I take it to mean that x is different from y. Then when I take the whole sentence into context, I know that X isn't Z, Y isn't Z, and X isn't Y.

--
Amy

7/28/2012 1:22:59 PM

Purple Pisces
Purple Pisces
Posts: 878
To me it's all in the way it's worded. It's amazing how just one or two words can change the meaning of a statement!

In the two statements Joshua posted about Bob:

Bob is neither a tall man nor an Italian

Bob is neither the tall man nor the Italian

Just by changing the "a" and "an" in the first sentence to "the" in the second sentence it takes on a different meaning to me. I'm much more inclined to believe that the tall man is not the Italian in the second sentence.
edited by Purple Pisces on 7/28/2012

2/17/2013 6:26:58 PM

dougiezerts
dougiezerts
Posts: 9
I admit I'm also confused by those type of clues! They should make them clearer.

9/1/2013 6:44:28 PM

acenine
acenine
Posts: 1
In every day conversations we infer meanings from not only the things that people say but the way they say them. So if someone says “Bob is neither the tall man nor the Italian” instead of “Bob is neither a tall man nor an Italian”, then we infer that Bob, the tall man, and the Italian are three different people. This inference, however, is based on linguistics, not logic. From either sentence, all that we can logically conclude is that Bob is not tall and he is not Italian. Here's the kicker though, a reworded statement like, "Neither the tall man nor the the Italian is Bob" would imply that we are dealing with three different people.

9/2/2013 9:10:55 AM

creamchz3@aol.com
creamchz3@aol.com
Posts: 947
I admire all you logic puzzlers! I really do. But they still give me headaches! CC

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