## LG condition question "unless"

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Easy-E

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Joined: Fri Feb 18, 2011 1:46 pm

### LG condition question "unless"

I'm having some trouble with the wording of a particular condition for an LG game. This one in particular says that "H is assembled on line 1 or else line 7". Now, is this just as different way of saying "H is on 1 or 7" or do I somehow give preference to putting H on 1?

dakatz

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Joined: Sat Mar 29, 2008 4:19 pm

### Re: LG condition question "unless"

All it means is "H is on 1 or 7". Its just telling you that it can't go anywhere else besides those two spots. There is no preference for either spot.

Easy-E

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Joined: Fri Feb 18, 2011 1:46 pm

### Re: LG condition question "unless"

dakatz wrote:All it means is "H is on 1 or 7". Its just telling you that it can't go anywhere else besides those two spots. There is no preference for either spot.

Thats what I figured, thanks. I'm stumped on a question from an otherwise easy linear game, so I feel like their must be something I missed, but all my other answers are right...hmmm.

dakatz

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Joined: Sat Mar 29, 2008 4:19 pm

### Re: LG condition question "unless"

emarxnj wrote:
dakatz wrote:All it means is "H is on 1 or 7". Its just telling you that it can't go anywhere else besides those two spots. There is no preference for either spot.

Thats what I figured, thanks. I'm stumped on a question from an otherwise easy linear game, so I feel like their must be something I missed, but all my other answers are right...hmmm.

PM it to me and I can definitely help you out. Logic games were my fav thing about the test.

alexonfyre

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Joined: Fri Dec 25, 2009 3:00 am

### Re: LG condition question "unless"

Technically "or else" is XOR, exclusive OR. In the context of this problem it is simply there for logical accuracy, however in other cases it would be logically significant. It means that "or both" is NOT implied or true, unlike a straight up "or" statement.

Like I said, it doesn't really make intuitive sense for something to be "assembled" on 2 different lines, so in that case it is just there to avoid confusion, because a student of logic is not supposed to let the intuitive nature of a problem interfere with direct logical implications of the conditions. In another context: "He could wear a blue sweater or red pants" and "He could wear a blue sweater or else red pants" clearly have different meanings.

Jeffort

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Joined: Wed Jun 18, 2008 4:43 pm

### Re: LG condition question "unless"

emarxnj wrote:I'm having some trouble with the wording of a particular condition for an LG game. This one in particular says that "H is assembled on line 1 or else line 7". Now, is this just as different way of saying "H is on 1 or 7" or do I somehow give preference to putting H on 1?

You're talking about the last game on PT#30 (December '99).

As described by alexonfyre, for this game it's an exclusive either/or, meaning that one of the two must be true and also that both cannot be true together, making the two things mutually exclusive. Some either/or conditions are inclusive, meaning that the rule requires at least one of the two conditions, but also ALLOWS for both to be true absent other explicitly stated or contextual/structural derived restrictions.

It is the context of the other game parameters that make it an exclusive either/or in this case since the stimulus dictates a 1-1 correspondence situation. Exactly 7 assembled on 7 lines, exactly 1 to a line, so it cannot be in both 1 & 7 in a valid hypo. As said, the word 'else' was basically included for additional clarity but LSAC didn't have to include it for the game to be the same and still logically valid since the other parameters logically determined whether it was inclusive or exclusive to prohibit BOTH from being possible at the same time.

Either/or relationships trip a lot of people up on the LSAT and have been the core feature of many LG's and LR problems that are rated high difficulty, meaning that a large % of people get them wrong.

The rule of thumb for LSAT purposes is that, interpreted BY ITSELF, a given rule/premise that dictates either/or that does not also dictate NOT BOTH is inclusive, allowing for the possibility of both. Exclusive either/or situations are created by the logical context you are reasoning within (the other premises/rules/conditions) if it is not explicitly stated.

This has been played on in several high difficulty in/out grouping games (see birds in the forest game for an inclusive either/or with lots of traps for people that treat it as exclusive) as well as in many hard LR questions.

Bottom line, examine the context/other premises to determine whether BOTH is left open to possibility when in doubt. If nothing says or establishes that you cannot have both, then having both could be true.

ldo5014

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Joined: Sat Jan 22, 2011 9:40 pm

### Re: LG condition question "unless"

emarxnj wrote:I'm having some trouble with the wording of a particular condition for an LG game. This one in particular says that "H is assembled on line 1 or else line 7". Now, is this just as different way of saying "H is on 1 or 7" or do I somehow give preference to putting H on 1?

I know this isn't specifically answering your question, but viewtopic.php?f=22&t=120471 (TLS1776's guide) has a worksheet and explanation for unless statements. Might be worth your time!