Questions/Mistakes in FL Drills

[moshei24]

This is all in reference to the drills' answers on page 45 and 46.

#12 has a mistaken inference.

WB F should not be an inference.

The diagram is: WB <-- M B --> F

So in order to get WB F, you'd need to travel across two "some trains" after reducing WB <-- M to WB M, which doesn't work.

Please let me know if I'm mistaken about any of this.

Thank you!

[Dave Killoran]

#12. The inference as stated in the answer key is correct, and is not in error. I suspect that given the approach you are using to this segment you may have missed the conceptual foundation that justifies this inference. See item #4 from page 31 for another example of this inference (which is an important inference because when this structure appears, that inference is usually the correct answer). Drawing that inference requires using some of the principles outlined on pages 27-28.

Thanks

[moshei24]

My mistake on number 12. I just Went over those pages and I see the mistake that I made it. Thank you.