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标题: 假设题如何取非 [打印本页]

作者: lawyer_1 时间: 2004-11-4 04:30
标题: 假设题如何取非

取非意思就是假如某个选项是错的。

大体有三种情况：

1. all----not all/some---none/always----not always/sometimes----never/everywhere---not everywhere/somewhere---nowhere/only one, exactly one---none, more than one/at least one, some---none

2. 对于选项为条件句，将必要条件取非。

3. 直接将谓语肯定变否定，或否定变肯定。

[此贴子已经被作者于2004-11-4 4:32:38编辑过]

作者: paopao 时间: 2004-11-4 08:42
谢谢lawyer

作者: leeon 时间: 2004-11-5 14:16

作者: 活在当下 时间: 2004-11-9 08:25

能对第二点举个例子吗。

谢谢了。

作者: lawyer_1 时间: 2004-11-9 08:47

if you get a high score of GMAT, you will be accepted by Harvard University.

取非为：if you get a high score of GMAT, you will NOT be accepted by Harvard University

作者: hpp920 时间: 2004-11-10 08:37
好贴!!!我还正准备问条件句怎么取非呢, 这回懂了!

作者: 活在当下 时间: 2004-11-10 10:06

搞定了。谢谢

作者: Bobbysoft 时间: 2005-3-23 23:12

p->q这个判断(有的称之为命题）从formal logic（形式逻辑)来说，应该是P且~q

if you get a high score of GMAT, you will be accepted by Harvard University.

It is not the case that if you get a high score of GMAT, you will be accepted by Harvard University.<=> You get a high score of GMAT and You won't be accepted by Harvard University.

这里的很多说法都和逻辑不同，我补充一下正确的逻辑取非是什么样子的：

~(p或q) <=>(~p)且（~q)

~(p->q)<=>p且~q

~(p且q)<=>(~p)或(~q)

~(p<->q)<=>(p且~q)或（~p且q)

[此贴子已经被作者于2005-3-23 23:16:42编辑过]

作者: livary 时间: 2005-8-9 22:36
顶一下

作者: ethyl 时间: 2005-8-9 23:11

好贴！

作者: xjlv128 时间: 2006-2-18 18:38

以下是引用Bobbysoft在2005-3-23 23:12:00的发言：

p->q这个判断(有的称之为命题）从formal logic（形式逻辑)来说，应该是P且~q

if you get a high score of GMAT, you will be accepted by Harvard University.

It is not the case that if you get a high score of GMAT, you will be accepted by Harvard University.<=> You get a high score of GMAT and You won't be accepted by Harvard University.

这里的很多说法都和逻辑不同，我补充一下正确的逻辑取非是什么样子的：

~(p或q) <=>(~p)且（~q)

~(p->q)<=>p且~q

~(p且q)<=>(~p)或(~q)

~(p<->q)<=>(p且~q)或（~p且q)

极是极是！但是lawyer-1说的是GMAT的“逻辑”，呵呵，培生要是来严谨的，我们的头岂不是又要大三圈！！

作者: nearmiss 时间: 2006-2-20 20:20

大家好，我是菜鸟。

我想请问一下取非后有什么作用呢，怎么再去判断选项的正确性？

不吝赐教！

作者: dreamchaserdan 时间: 2006-2-22 23:35
标题: 回复：（nearmiss）大家好，我是菜鸟。我想请问一下...
引用lawyer的方法，将选项取非，原文结论不成立，则为正确选项。

作者: xjlv128 时间: 2006-3-11 10:58
嗯，是假设题的做法。如果它的反面能导致结论错误，它就不可少，所以是assumption.

作者: amber0919 时间: 2006-4-14 15:39

作者: amber0919 时间: 2006-4-14 15:46

195.

A proposed change to federal income tax laws would eliminate deductions from taxable income for donations a taxpayer has made to charitable and educational institutions. If this change were adopted, wealthy individuals would no longer be permitted such deductions. Therefore, many charitable and educational institutions would have to reduce services, and some would have to close their doors.

The argument above assumes which of the following?

(A) Without the incentives offered by federal income tax laws, at least some wealthy individuals would not donate as much money to charitable and educational institutions as they otherwise would have.

(B) Money contributed by individuals who make their donations because of provisions in the federal tax laws provides the only source of funding for many charitable and educational institutions.

(C) The primary reason for not adopting the proposed change in the federal income tax laws cited above is to protect wealthy individuals from having to pay higher taxes.

(D) Wealthy individuals who donate money to charitable and educational institutions are the only individuals who donate money to such institutions.

(E) Income tax laws should be changed to make donations to charitable and educational institutions the only permissible deductions from taxable income.

Choice A is the best answer, since if this statement is false, all wealthy individuals would, even without the incentive provided by federal tax laws, donate as much money as they do now. In that case, the evidence used in the argument provides no support for the conclusion.

ＯＧ把Ａ取非：at least some---＞all　怎么是这样取的呀？？？　不应该是at least some－－－＞none吗？？

作者: keer1977 时间: 2006-4-20 00:11

at least some wealthy individuals would not donate as much money to charitable and educational institutions as they otherwise would have.

是不是应该这样: none wealthy inviividuals would donate as much money to charitable and educational institutions as they otherwise would have.

作者: amber0919 时间: 2006-4-21 15:37

不能那样取.那样取非结论还是成立的.就应该象OG那样区非:all wealthy individuals would, even without the incentive provided by federal tax laws, donate as much money as they do now.

但我不知道为什么。

作者: numberunique 时间: 2006-5-13 11:55

以下是引用amber0919在2006-4-21 15:37:00的发言：

但我不知道为什么。

all wealthy individuals would

与

none wealthy individuals would not

不是一样吗

作者: amber0919 时间: 2006-5-13 12:16
谢谢.果然是这样..

作者: jandjshi 时间: 2006-6-6 13:34

全称肯定 (Everybody Did) 和特称否定(Somebody Did NOT)是矛盾关系

全称否定(Everybody did NOT=nobody did) 和特称肯定(Somebody did)是矛盾关系。

at least some wealthy individuals would not donate 取非为 every wealthy individual would donate.

作者: sabrina07 时间: 2006-8-28 21:23
ding!

作者: fengyun1 时间: 2006-8-31 16:45

好好的研究了一把。值得收藏。

作者: wangjianxiu 时间: 2006-9-25 22:01
thank you 爱你们

作者: 水里游 时间: 2008-10-8 19:13

作者: shuiyueyou 时间: 2009-6-23 12:04

头晕了~~

作者: pumpkinhuo 时间: 2009-6-25 19:03

以下是引用lawyer_1在2004-11-4 4:30:00的发言：

取非意思就是假如某个选项是错的。

大体有三种情况：

1. all----not all/some---none/always----not always/sometimes----never/everywhere---not everywhere/somewhere---nowhere/only one, exactly one---none, more than one/at least one, some---none

2.对于选项为条件句，将必要条件取非。

3。直接将谓语肯定变否定，或否定变肯定

请教：黄线部分不明白什么意思。。

only one, exactly one 中间的逗号是什么意思。。。

作者: yuromeo 时间: 2009-11-20 10:23
支持一下

作者: icefiremin 时间: 2010-1-15 21:57

取非意思就是假如某个选项是错的。
大体有三种情况：
1. all----not all/some---none/always----not always/sometimes----never/everywhere---not everywhere/somewhere---nowhere/only one, exactly one---none, more than one/at least one, some---none

有个疑问，是不是取非有时也有两种结果？比如：

some---none或all

sometimes---never或always

everywhere---not everywhere或nowhere

somewhere---nowhere或everywhere

作者: finvina 时间: 2010-4-18 09:26

有个疑问，是不是取非有时也有两种结果？比如：

some---none或all

sometimes---never或always

everywhere---not everywhere或nowhere

somewhere---nowhere或everywhere

-- by 会员 icefiremin (2010/1/15 21:57:54)

我觉得不是你说的这样。
取非应该就是只有一种结果。1. all----not all/some---none/always----not always/sometimes----never/everywhere---not everywhere/somewhere---nowhere/only one, exactly one---none, more than one/at least one, some---none

但是，如果句子是 some...not ，那取非后就是none...not，即是all
你说的其他各项就是：
some...not--->none...not=all

sometimes...not--->never...not=always

everywhere...not--->not everywhere...not=nowhere

somewhere...not--->nowhere...not=everywhere

作者: rinelylove 时间: 2010-5-9 21:58
标题: 请问版主啊~你的第2点是什么意思，可否具体点呢，举个例子好吗？
谢谢啊

作者: 优由圈 时间: 2010-6-16 00:13
谢谢咯~

作者: larryywddd 时间: 2010-12-17 16:51
NN

作者: GMAT冲冲冲 时间: 2011-9-7 18:17
标题: 求解
lawyer有说直接把谓语的肯定变否定或者否定变肯定，那some.......not不是只要把后面的not省略就好了么~本人愚笨，希望得到解答~

作者: marseill 时间: 2012-11-23 01:20

有个疑问，是不是取非有时也有两种结果？比如：

some---none或all

sometimes---never或always

everywhere---not everywhere或nowhere

somewhere---nowhere或everywhere

-- by 会员 icefiremin (2010/1/15 21:57:54)

-- by 会员 finvina (2010/4/18 9:26:17)

他那个例子应该是两种,也可以说是一种或多种, some取非是 not some, 而not some包括 none和all.

作者: marseill 时间: 2012-11-23 01:34

lawyer有说直接把谓语的肯定变否定或者否定变肯定，那some.......not不是只要把后面的not省略就好了么~本人愚笨，希望得到解答~

-- by 会员 GMAT冲冲冲 (2011/9/7 18:17:32)

取非some,和取非not都可以.如原文是 some people don't eat apples.
取非not,就是一些人吃.
取非some比较绕口,就是: not some...not, 非一些人不吃. 意思就是,不是只有一个人吃的和不是所有人一起吃.
在这两个情况之外就是一些人吃.
也就是双重否定变肯定啦~ 取非谁,都一样

作者: Feelalive 时间: 2013-6-6 17:27
非常感谢

作者: msripper 时间: 2014-10-31 14:46
mark,great job

作者: lqcindy 时间: 2015-8-4 17:16
感谢分享！

作者: emiliana 时间: 2015-10-18 11:20
感谢分享！

作者: 不喜欢乱起名字 时间: 2016-3-7 00:36
Mark一下！

作者: WJWJWJWJ 时间: 2016-8-7 11:00
请问这一句：
people will reduce their trash output by reducing the products they buy.
该对谁取非呢？

作者: Elaine六便士 时间: 2019-9-26 06:03
赞

作者: tiyuduncaogu 时间: 2019-10-21 11:38
感谢分享！

作者: Lyc2022 时间: 2021-7-15 20:24
顶楼主！

作者: 0320zjx 时间: 2023-3-22 17:49
感谢分享！

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