Grouping Setup Practice Drill #2

[megmeg123]

It seems like the most "important" inference we can draw from the F C D relationship is that F D, however, in the explanation of this drill, I'm told that another inference (that's not important for LG, but for LR) is that some Gs are not Cs, couldn't I also make the inference that some Gs are not Fs? Just curious

Thanks for your help!

[Nikki Siclunov]

Hi megmeg123,

Yes, that's also an inference you can make.. just don't expect it to be terribly useful in LG.

Here's how I would link up the conditional statements in this drill:

• F C D G

The following can be inferred:

• F D
  G NOT C
  G NOT F

Good job on this one!

[megmeg123]

Hi megmeg123,

Yes, that's also an inference you can make.. just don't expect it to be terribly useful in LG.

Here's how I would link up the conditional statements in this drill:

• F C D G

The following can be inferred:

• F D
  G NOT C
  G NOT F

Good job on this one!

Thanks for all your help!

[Dave Killoran]

Here's how the two "some are not" inferences discussed in the book are made:

First, for the G to C inference, start with the chain relationship:

• C D G
  
  From G, we can ride "backwards" over the arrow (which is a "some" relationship going that direction) to D. From D, we can ride to C, and there's a negative there. The lowest strength term along the chain is "some," and so the inference is G C.

Second, for the G to F inference, reuse the F D inference, and add G to the chain relationship:

• F D G
  
  From G, we can ride "backwards" over the arrow (which is a "some" relationship going that direction) to F, and there's a negative there. The lowest strength term along the chain is "some," and so the inference is G F.