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General questions relating to LSAT Logical Reasoning.
 Jay
  • Posts: 46
  • Joined: Jan 09, 2020
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#84610
Hi I have another general conditional logic question. Thank you always for your help...

I don't always know how to diagram in a "BEST" way. Sometimes there are a number of different ways to diagram and I sometimes don't know which is the most ideal version.

For example, if in the stimulus, I see "I am allergic to anything that has peanut."

I diagrammed as

"I -> allergic to peanut"

But the best form for the question was

"Peanut -> am allergic to it"

This may seem like a subtle difference. Of course if I have enough time, I know how to come up with the best form, But under timed constraints, I can't.

Little word of advice please.

Thank you!
 Jeremy Press
PowerScore Staff
  • PowerScore Staff
  • Posts: 1000
  • Joined: Jun 12, 2017
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#84638
Hi Jay,

For this statement you needed to use the conditional "indicator" word as a guide to what to diagram on the proper side of the arrow. First things first, remember that every conditional diagram should be ordered as:

[Sufficient Condition] :arrow: [Necessary Condition]

So we're trying to look at the statement and identify what the sufficient condition is, and what the necessary condition is. The simplest way to start learning to do that is to use "indicator" words as your guides to what is the sufficient condition, and what is the necessary condition.

There is one such indicator word in the sentence you provided, the word "anything" (which is the same thing as the term "any"). "Any" (or, in this case, "anything") is a sufficient condition indicator. Since "anything" modifies "has peanuts," peanuts are your sufficient condition and they belong on the left side of the arrow diagram.

Peanuts :arrow:

Now we have to look at what remains in the sentence (what idea in the sentence wasn't "covered by" the sufficient condition I just diagrammed). That's the first part of the sentence, "I am allergic." That idea will get diagrammed as the necessary condition, on the right side of the arrow.

Peanuts :arrow: I am allergic

Translating that into a simple "if...then..." so that I cement the relationship for myself, produces this: "If it has peanuts, then I am allergic to it." Now we've got it!

The "indicator" words (for sufficient and necessary conditions) should ideally be memorized. I can rattle them off in my sleep, and you should try to get to that point too, because it will give you a huge jump start with the diagramming process. Those indicators can be found in the Conditional Reasoning chapter of the Logical Reasoning Bible, in Lesson 2 of our online course books, and in some other places as well.

I hope this helps!
 Jay
  • Posts: 46
  • Joined: Jan 09, 2020
|
#84987
Thank you! This really helps!

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