P: not E → not FP: F–some–GC: ?

Hunter June 26, 2019

Does F exist?

Two days ago I got a very similar question wrong for assuming that a sufficient variable existed. How do I know when it exists and when it doesn't?

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Ravi June 27, 2019

@Hunter,

Happy to help. Let's take a look at this question.

P: not E - >not F (F - >E)
P: F-some-G (G-some-F)
C:

What can we conclude?

We know that all Fs are Es and we also know that some Fs are Gs

F - >E
F-some-G (G-some-F)

G-some-F - >E

This means that there must be some Es that are Gs

E-some-G

Does this make sense? Let us know if you have any other questions!

Hunter June 27, 2019

Only Daily Drills 52 a premise was that all leprechauns were shoemakers and no leprechauns are females.

I assume I can conclude that some shoemakers are not females. However, the right answer was NVC, because I couldn't assume leprechauns existed.

So, I still don't get how I can conclude E-some-G, if I don't know if F ever existed. Is it because of some?