"Unless" statement Brainfart!

Prepare for the LSAT or discuss it with others in this forum.
brooklynballers

New
Posts: 16
Joined: Sat Feb 20, 2010 4:25 pm

"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?

User avatar
doyleoil

Silver
Posts: 628
Joined: Sat Oct 11, 2008 2:59 pm

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)

User avatar
artichoke

Silver
Posts: 760
Joined: Mon Jun 21, 2010 11:20 pm

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

New
Posts: 16
Joined: Sat Feb 20, 2010 4:25 pm

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

New
Posts: 76
Joined: Thu Oct 09, 2008 7:59 pm

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

User avatar
doyleoil

Silver
Posts: 628
Joined: Sat Oct 11, 2008 2:59 pm

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

New
Posts: 76
Joined: Thu Oct 09, 2008 7:59 pm

Re: "Unless" statement Brainfart!

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

Edit: What doyle said

brooklynballers

New
Posts: 16
Joined: Sat Feb 20, 2010 4:25 pm

Re: "Unless" statement Brainfart!

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

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

User avatar
Jeffort

Gold
Posts: 1888
Joined: Wed Jun 18, 2008 4:43 pm

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

User avatar
blackwater88

Bronze
Posts: 197
Joined: Tue Feb 09, 2010 1:40 pm

Re: "Unless" statement Brainfart!

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

unless: if not
DONE

brooklynballers

New
Posts: 16
Joined: Sat Feb 20, 2010 4:25 pm

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

Bronze
Posts: 317
Joined: Tue Jun 29, 2010 5:21 pm

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."

User avatar
Jeffort

Gold
Posts: 1888
Joined: Wed Jun 18, 2008 4:43 pm

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.

User avatar
blackwater88

Bronze
Posts: 197
Joined: Tue Feb 09, 2010 1:40 pm

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

New
Posts: 90
Joined: Wed Jan 20, 2010 3:00 pm

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.



Return to “LSAT Prep and Discussion Forum�

Who is online

Users browsing this forum: No registered users and 16 guests