If Archimedes was tall, then Euclid was shirt. Euclid was not short unless Pythagoras was fat. Pythagoras was fat only if he ate too much. Pythagoras did not eat too much. Therefore, Archimedes was not tall. Isthe above logic inference valid? Show your inference step!
請問這題如何解??
謝謝大家
6 則留言:
題目給:
1. A tall => E short
2. E short => P fat
3. P fat => P ate too much
則 !(P ate too much)
=> !(P fat)
=> !(E short)
=> !(A tall)
所以若 P 沒有吃太多, 那 A 真的不高
雖然未影響答案
但依題目敘述
2和3 應該是 <=>
若且唯若的條件
我的看法不一樣
麻煩公告者出示一下答案
A tall -> E short
Euclid was not short unless Pythagoras was fat.
第二句他說 E not short 除非 P fat
反過來說應該是 P fat -> E not short
第三句沒甚麼幫助
p eat too much <=> p fat
總結
A tall -> E short
P fat -> E not short
p eat too much <=> p fat
現在給了 Pythagoras did not eat too much 也就是 p not fat
根據第二句 若 p 則 q
~p 則 甚麼都不是
所以Archimedes was not tall根本就不關他的事情了
1. A unless B 等價於 ~A->B
2. 第三句是 "...only if...",
不是if and only if, 所以只有一個方向
感謝 wynne 大
你是對的
請你問之道還有哪些英文是用在邏輯的麼
像是 A unless B = ~A -> B
if A then B = A -> B
A only if B = ? 只有B的情況下才會A才對
還有甚麼可以解答我疑惑的麼
感激不盡
這我一時也想不到其它的, 其實比較常出現的大概就這些, 不過我想以後你若有遇到類似的問題, 如果我幫得上忙的話, 我很樂意到時再幫你回答
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