作者MathTurtle (恩典)
看板logic
标题Re: [请益] symbolize
时间Tue Feb 23 19:54:29 2010
※ 引述《Searle (♂拥抱後的寂寞♀)》之铭言：
: 有几个symbolize的疑惑想请高人指点一下..
: Let Sx = "x is a student"
: Cx = "x is a course"
: Txy = "x takes y"
: Ixy = "x is more interesting than y"
: Dx = "x is demanding"
: 1. Some student don't take any courses that are more interesting than the courses John take.
: ∃x(Sx Λ (y)[(Cy→(z)[(Cz Λ Tjz)→Iyz] Λ ~Txy)
: 这样写有错吗？
你这样写的意思是:
some students are such that every course is more interesting
than any course john takes and these students don't take it.
换言之, 它蕴含: Some students don't take any course.
比较好的翻法应该是:
∃x(Sx Λ (y)[(CyΛ(z)[(Cz Λ Tjz)→Iyz] → ~Txy)])
: 2. Only good students take demanding courses.
: (x){[Sx Λ (y)((Cy Λ Dy)→Txy)]→Gx}
: 3. Good student won't take courses unless they are demanding.
: 不晓得这个they是指student还是course..
: 恳请指教!
是指course吧, 讲一个学生demanding有点怪。
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 81.107.38.67
※ 编辑: MathTurtle 来自: 81.107.38.67 (02/23 19:56)