p->q这个判断(有的称之为命题)从formal logic(形式逻辑)来说,应该是P且~q
if you get a high score of GMAT, you will be accepted by Harvard University.
It is not the case that if you get a high score of GMAT, you will be accepted by Harvard University.<=> You get a high score of GMAT and You won't be accepted by Harvard University.
这里的很多说法都和逻辑不同,我补充一下正确的逻辑取非是什么样子的:
~(p或q) <=>(~p)且(~q)
~(p->q)<=>p且~q
~(p且q)<=>(~p)或(~q)
~(p<->q)<=>(p且~q)或(~p且q)
[此贴子已经被作者于2005-3-23 23:16:42编辑过] |