LSAT考试技巧:条件的逻辑表达式b
A,B不相对 A<-/->B A,B are two spaces apart(A,B相隔为2) (A□B) or |A-B|=2 * Two spaces separate A and B = A,B are two spaces apart 又如:A is two floors above B, 则A和B只有一层相隔 又如:A is two days before B, 则A与B之间只有一天之隔 区别:A,B之间有两个元素 (A□□B) A is to the right of B: B-A A is to the immediate right of B: AB B is to the right of either A or C, but not both: (A-B-C) or A/C——B——A/C 区别:B is between A and C: A-B-C 区别:B is immediately between A and C: (ABC) =B is (immediately) next to both A and C. If A is next to B, it is not next to C: ~(BAC) 2.表选择 If A, then B(A入选则B入选) A→B 逆反命题 -B→~A 选A则不选B A→~B (但可同时不选) =A,B不全选 A→~B 逆反命题 B→~A(区别A,B全不选) 同理:A灯亮则B灯灭 A→~B 逆反命题 B→~A (但A,B可同时灭) 另外:A is off if and only if either B or C is on: B/C→~A (B和C可同时亮时A也不亮) 逆反命题 A→ ~B/C (A亮时,B,C都不能亮,即neither A nor B is on=both off) If A, then B, and if B, A: A<——>B =If A, then B, and if ~A, ~B =A if and only if B =B if and only if A =Neither A nor B unless the other is selected. A only if B: A→B 逆反命题 B→~A A unless B: ~A——>B 逆反命题 ~B→A 区别:Not A unless B: A→B 逆反命题 B→~A Only A works in the afternoons: only A=pm 区别:A only works in the afternoons: A=pm If A occurs in a word, it occurs an odd number of time: J→J=odd# Only As are Bs: B→A =only if A, B No As are Bs. A≠B (A,B无交集) |