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2008/03/02 21:27:32瀏覽476|回應0|推薦3 | |
B-1 There are ghosts. 轉化成述詞邏輯語句依序經過四次改寫: 第一步改寫:There is something such that it is a ghost. 第二步改寫:There is something y such that y is a ghost. 第三步改寫:(∃y)(y is a ghost) 第四步改寫:(∃y)(Gy)
C-1 (x)(x is in motion ∨x is at rest) 要回答第一個問題之前,要先回答第二個問題,亦即是題目中的變元究竟是自由的還是拘限的,而這樣看變元是否指涉到量詞而定,若變元有指涉到量詞,則為拘限變元,否則就是自由變元。因此此題的x是拘限變元,而自由變元無法用來符號化語句也不能用來檢測量化邏輯的論證,只有拘限變元可以,因此這題可表達出有真假可言的語句。
D-1 (∃x)(x is ancient ∨ x is modern) 第一步改寫:There is something x is such that x is ancient or x is modern 第二步改寫:There is something is such that it is ancient or it is modern 第三步改寫:Something is ancient or modern 第四步英翻中:有些東西是古代的或現代的。 |
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( 知識學習|隨堂筆記 ) |