SDCAR2010【逻辑入门】（十五）More on Negation

sdcar2010

亲爱的楼主~~还有更新么？！

-- by 会员 happybeibei (2011/9/4 11:36:17)

I am at my wits' end. What else do you want to learn?

sandychen168

Here, we are talking about logical opposite vs. polar opposite. Will not is the polar opposite of will. "Will" mean definitely YES and inevitably YES! "Will not" means defintely NO and inevitably NO. However, in CR we are talking about LOGICAL opposite. Might and Might not means NOT definitely YES, not certain.

dear SDCAR~
I'm rather confused by this negation

Verbs                                             | Negation
will                                                  |  might, might not (Another case of paradox!)

Why the negtion of "will" is "might" and "might not" but not "will not".

Thank you!!!

-- by 会员 sandychen168 (2011/9/1 17:15:29)

-- by 会员 sdcar2010 (2011/9/4 11:56:49)

Thank you!!!!

caoqin1981

否的范围和度好像很难把握嘛

lq0

then why boht "if" and "then" clauses have to be negated in contrapositive? contrapositive means we have to negate as well as switch. in both cases, we have to negate.

help~~~~~~~~~~~~~~~~~~

sdcar2010

In contrapositive, we want to find a CORRECT statement if the original statement is correct.

In negation for necessary assumption question, we want to find a statement which, when negated, would NOT lead to the orignial conclusion in the end.

then why boht "if" and "then" clauses have to be negated in contrapositive? contrapositive means we have to negate as well as switch. in both cases, we have to negate.

help~~~~~~~~~~~~~~~~~~

-- by 会员 lq0 (2011/10/7 15:55:44)

bonfin

quantity             negation
100                     0~99
1~100                    0

nobody910

请问SDCAR，negation（logical opposite）是不是就是说命题的否定。而polar opposite则是指完全相反，相当于取补集。

negation与polar opposite的关系跟  命题的否定和否命题的关系   是两回事吧？

THX!

Here, we are talking about logical opposite vs. polar opposite. Will not is the polar opposite of will. "Will" mean definitely YES and inevitably YES! "Will not" means defintely NO and inevitably NO. However, in CR we are talking about LOGICAL opposite. Might and Might not means NOT definitely YES, not certain.

dear SDCAR~
I'm rather confused by this negation

Verbs                                             | Negation
will                                                  |  might, might not (Another case of paradox!)

Why the negtion of "will" is "might" and "might not" but not "will not".

Thank you!!!

-- by 会员 sandychen168 (2011/9/1 17:15:29)

-- by 会员 sdcar2010 (2011/9/4 11:56:49)

sdcar2010

Negation 相当于取补集 or anything BUT (the original statement).

Polar opposite is COMPLETE opposite of (the original statement).

812966141

先顶再看

晓野的野

赞赞赞 有时候取非不知道取哪个 这样一看清楚多了！