A ->B
~( C ^ B)
C
________________
therefore ~A
Anyone know? I'm hopelessly clueless...
2006-10-12 04:06:53 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
If A then B, if C it can't be B also. That would be against the 2nd statement
if the car crashed I was driving it
can't be that both me and you were driving it
you were driving it
therefore the car didn't crash
2006-10-12 04:09:10 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The contrapositive form of writing the implication (or conditional statement) if A then B is if NOT B then NOT A.
from ~(C ^ B) we get ~C or ~B
from C we get ~B
~A
2006-10-12 11:17:32 · answer #2 · answered by bob h 3 · 0⤊ 0⤋
1. A -> B is equivalent to ~B -> ~A
2. ~(C ^ B) means ~C v ~B
if we assume C to be true well as the other two statements, then
~C is false and
then ~B must be true (because at least one of the statements {X,Y} of X v Y must be true for X v Y to be true), thus ~A is true.
2006-10-12 11:14:34 · answer #3 · answered by Jay 3 · 1⤊ 0⤋
Work backwards:
C is true.
~(C ^ B) is true, therefore B must be false to make C ^ B false.
And since A -> B also means ~B -> ~A, ~A. (QED)
2006-10-12 11:10:18 · answer #4 · answered by Dave 6 · 2⤊ 0⤋
just say yes. no problem
2006-10-12 11:09:49 · answer #5 · answered by indike111 4 · 0⤊ 1⤋