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# Negation Help !

Alum Member
in General 243 karma
Some A's are not B's

A's -----> not B 's
(some)

What if I want to negate some A's are not B's?

would the negation be ....

B's ---> not A's some B's are not A's?
(some)

or would it be
no A's are not B's?
A->B?
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• #### Help with negation!Are these two sentences mean the same thing? Some people do not enjoy the movie. Not all people enjoy the movie. I wonder if "not all" and "so…

• Member Inactive ⭐
2424 karma
The negation of some A's are not B's is essentially all A's are B's. Think about it A--->B
• Alum Inactive ⭐
edited March 2015 3438 karma
There's a lesson about this in the curriculum... the negation of some As are not Bs will not be some Bs are not As - remember there is no arrow in some... here you are essentially saying the same thing... some speaks of a range... 1 - the full set... therefore the only 'negation' of some would be none... a clean binary cut: NO A's are not B's
• Alum Member
edited March 2015 243 karma
Ah thanks guys !

So what if I got something like
Some apples are not green
A ----> not G
(some)

Negation would be...

All apples are green?

A---G?

Opposite of ALL= not some ?
Opposite of some=none or could be all?

Some apples are Not green

A---> not G = Opposite ---> A->G
(some)
• Alum Inactive ⭐
3438 karma
yep all apples are green (no apples are not green)
• Alum Member
243 karma
THANK YOU guys! and thank you Sage ! Lord I have learned more here than I did in over priced prep classes. And I been studying just few weeks!!!!
• Alum Member Inactive ⭐
3462 karma
EXISTENTIAL QUANTIFIERS BRIEF Lesson 3of 30
• There exist things such as ______ (fill in the blank- predict)
Ex: happy people v. poor people (middle intersection)
• Indicators: “SOME”
• **No such thing as a contrapositive- it does NOT exist for EXISTENTIAL QUANTIFIERS

“SOME” STATEMENTS MEANING Lesson 4 of 30
• EQ
• "Some speaks of a range”-> “All speaks of a point (100)”
• Definition of “some” is at least 1
• Starts at 1 to 100 (does not include 0)
• Ex: Some dogs are playful (1-100) → all dogs are playful (100)
• Lower bound: 1
Upper bound: 100
• 0 is not included in Some

“SOME” STATEMENTS TRANSLATE Lesson 5 of 30
• [Some] dogs (D) are cute (C)
D some C
*Some is an intersection that’s why it does not carry an arrow
• NO SUCH THING AS A CONTRAPOSITIVE =/= /D some /C- YOU KNOW TOO LITTLE TO DETERMINE IF (NON-DOGS ARE NOT CUTE? HOW DO YOU KNOW? YOU DON’T KNOW!)

**ADVANCED: NEGATE SOME STATEMENTS Lesson 13 0f 30**
• Some – None
• Ex: Some dogs are brave
D some B
• Negate [No] dogs are brave
D→ /B
B→ /D
• All- Some Not
• Alum Member
243 karma
@emli1000 , you have note there that there is no such thing as a contrapositive for....

Some dogs are cute
D some C (bc. none dogs are not cute? not enough info)

But then D some B
-there is a contrapositive
No dogs are brave
D->/B

So is that because of context?
because when I look at D some C, I automatically think well it is "some" to negate some we go to "none"

D->not C
No dogs are cute?
• Alum Member
243 karma
@emli1000, btw did you post your notes for all the lessons? or I think I just have the Logic reason one? lol, if you do not mind sharing
• Alum Member Inactive ⭐
3462 karma
Some cannot have a contrapositive such as you CANNOT have /A SOME /B because remember that SOME is an intersection.

If you negate SOME then you'll end up with NONE. If you follow the lesson from my notes in the Some and Most relationships and watch those videos along with my notes it will make more sense. Trust me. I was stuck on that lesson because I felt like it wasn't making any sense.
• Alum Member
243 karma
Thank you so much ! I will go back and review the lesson. I think I am starting to catch on a little bit
• Alum Inactive ⭐
3438 karma
^^ this.... it is one of the biggest takeaways you can have and you should get this down pat as you will definitely be tested on your knowledge of some/most/all on the LSAT.
• Alum Member Inactive ⭐
3462 karma
No problem
• Alum Member
243 karma
• Alum Member Inactive ⭐
3462 karma
I actually found an excellent example for you!

PT 39 Sec. 2 Q#21
• Alum Member
243 karma
just saw thank you!
• Alum Member Inactive ⭐
3462 karma
I'll send them to you whenever I find more. It's helpful watching the video explanations.