"Unless" statement Brainfart!

brooklynballers
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"Unless" statement Brainfart!

Postby brooklynballers » Wed Jun 30, 2010 5:16 pm

N cannot be selected unless L is selected.

Isn't this supposed to diagrammed as L --> N?

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doyleoil
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Re: "Unless" statement Brainfart!

Postby doyleoil » Wed Jun 30, 2010 5:21 pm

brooklynballers wrote:N cannot be selected unless L is selected.

Isn't this supposed to diagrammed as L --> N?


just the opposite (meaning, N ---> L)

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artichoke
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Re: "Unless" statement Brainfart!

Postby artichoke » Wed Jun 30, 2010 5:24 pm

No. N--->L

if N is selected, you know L has been as well because N can only be selected if L is.

brooklynballers
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Re: "Unless" statement Brainfart!

Postby brooklynballers » Wed Jun 30, 2010 5:25 pm

doyleoil wrote:
brooklynballers wrote:N cannot be selected unless L is selected.

Isn't this supposed to diagrammed as L --> N?


just the opposite (meaning, N ---> L)


Could you explain the process of getting to your diagram?

agentcom
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Re: "Unless" statement Brainfart!

Postby agentcom » Wed Jun 30, 2010 5:25 pm

Umm it's been a while, but wouldn't it be:

~L --> ~N

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doyleoil
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Re: "Unless" statement Brainfart!

Postby doyleoil » Wed Jun 30, 2010 5:27 pm

agentcom wrote:Umm it's been a while, but wouldn't if be:

~L --> ~N


This isn't a bad place to start, because I think the best, most common sense, way to get to the diagram is to say to yourself "what happens if L isn't there?" If L isn't there, then N isn't there. And the contrapositive of that is "N ----> L"

agentcom
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Re: "Unless" statement Brainfart!

Postby agentcom » Wed Jun 30, 2010 5:28 pm

Edit: What doyle said

brooklynballers
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Re: "Unless" statement Brainfart!

Postby brooklynballers » Wed Jun 30, 2010 5:29 pm

So you could select L, but not necessarily select N right?

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Jeffort
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Re: "Unless" statement Brainfart!

Postby Jeffort » Wed Jun 30, 2010 5:31 pm

brooklynballers wrote:So you could select L, but not necessarily select N right?


Yes

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blackwater88
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Re: "Unless" statement Brainfart!

Postby blackwater88 » Wed Jun 30, 2010 5:34 pm

unless: if not
DONE

brooklynballers
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Re: "Unless" statement Brainfart!

Postby brooklynballers » Wed Jun 30, 2010 5:41 pm

blackwater88 wrote:unless: if not
DONE


So the best way to think of it would be:

N can not be selected (if not) L is selected
OR
N can not be selected if L is not selected.

Which gives us:
If L is not selected, then N is not selected.

Contrapositive:
N --> L

Audio Technica Guy
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Re: "Unless" statement Brainfart!

Postby Audio Technica Guy » Wed Jun 30, 2010 5:57 pm

"if not" works. Some people have just as hard of a time with if not as they do with unless though, and if that is the case, just think "whatever comes immediately after unless goes on the right side, the other thing goes on the left and negated."

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Jeffort
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Re: "Unless" statement Brainfart!

Postby Jeffort » Wed Jun 30, 2010 6:04 pm

Audio Technica Guy wrote:"if not" works. Some people have just as hard of a time with if not as they do with unless though, and if that is the case, just think "whatever comes immediately after unless goes on the right side, the other thing goes on the left and negated."


I like the 2nd one bolded above more. It is less confusing and faster since it is pretty brainless and mechanical with less translation steps.

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blackwater88
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Re: "Unless" statement Brainfart!

Postby blackwater88 » Wed Jun 30, 2010 6:18 pm

Jeffort wrote:
Audio Technica Guy wrote:"if not" works. Some people have just as hard of a time with if not as they do with unless though, and if that is the case, just think "whatever comes immediately after unless goes on the right side, the other thing goes on the left and negated."


I like the 2nd one bolded above more. It is less confusing and faster since it is pretty brainless and mechanical with less translation steps.


To me "if not" works much faster, to be honest I first learned the bolded part, when I thought about "if not" it made me doubt since I didn't grasp the concept of "unless" that well. However, if you just take it as it is and substitute "unless" for "if not" every time it appears, there really is no transitional thinking. Just like you should memorize that all As are Bs = A ==> B

Unshake
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Re: "Unless" statement Brainfart!

Postby Unshake » Wed Jun 30, 2010 7:22 pm

If you're using the logical reasoning bible, check out page 126 and maybe review all of chapter six. Basically what is explained here is correct; if you see the word "unless" (and some other words like until or except) whatever is modified by this becomes the necessary condition.




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