Daily Drills 15 - Section 15 - Question 4

P: A–most–BP: ?C: A–most–not X

kayanamcobb August 5, 2016

Diagramming "Most"etc

I feel pretty comfortable overall with diagramming suff & nec conditions in formal logic. But I am still a bit unclear on how the chain works from "most" to "some" I know that "some" is a double arrow and "most" is not...but I'm not sure I always know when it's supposed to change to "some" when I'm combining statements and making inferences or providing missing premises. Is there any resource I can visit for more clarity / instruction on this?

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Mehran August 7, 2016

@kayanamcobb we do not use arrows to diagram quantifiers (i.e. some or most) because these concepts are very different from Sufficient & Necessary conditions.

"Some" statements and "most" statements are reversible with the only caveat being that "most" becomes "some" when you reverse it.

So for example:

A-some-B can be reversed to B-some-A.

A-most-B can also be reversed to B-some-A.

Hope this makes sense!

For a more in-depth discussion of these concepts, please watch our video lesson on Quantifiers.

kayanamcobb August 30, 2016

Thank you!