[求助] 到底Assumption是什么？？？？

如果有三段论

1 A -> B 而且 2 B->C

则有结论  3 A->C

简写为 1 premises & 2 assumption => 3 conclusion

但是在做OG第8题的时候，好像有【结论 -> Assumption】感觉

OG10第8题

8.

To prevent some conflicts of interest, Congress could prohibit high-level government officials from accepting positions as lobbyists for three years after such officials leave government service. One such official concluded, however, that such a prohibition would be unfortunate because it would prevent high-level government officials from earning a livelihood for three years.

The official’s conclusion logically depends on which of the following assumptions?

A. Laws should not restrict the behavior of former government officials.

B. Lobbyists are typically people who have previously been high-level government officials.

C. Low-level government officials do not often become lobbyists when they leave government service.

D. High-level government officials who leave government service are capable of earning a livelihood only as lobbyists.

E. High-level government officials who leave government service are currently permitted to act as lobbyists for only three years.

8.

关于B答案的排除

The official’s argument does not depend on the assumption in B, since the argument would not be invalidated if lobbyists were not typically former high-level government officials.

可以视为 非Assumption    无法推出    非结论，

其实也就是用如果有那个assumption满足：

非Assumption    ->     非结论 则这个Assumption就是conlcusion depends on 的Assumption

用逆反命题的原则就应该有  结论 -> Assumption

这个和Premises + Assumptions -》 Conclusion 有矛盾啊

assumption 有两种：充分性 and 必要性
充分性就是架桥的意思

Congress prohibit gov officials from accepting positions as lobbyists

推出

prevent gov officials from earning a livelihood

position as lobbyists 与 earning a livelihood之间没有桥梁

这道题就是充分性assumption, 所以要架桥
答案就是gov officials earning a livelihood only as lobbyists

关于assumption可以看NN的分析

http://forum.chasedream.com/dispbbs.asp?BoardID=24&ID=402511&replyID=&skin=0