@quinnxzhang said:
In classical logics, there's something called the deduction theorem (https://en.wikipedia.org/wiki/Deduction_theorem) which intimately relates these two things, i.e. "if P, then Q" is valid if and only if "P. Therefore, Q" is val…
@tanes256 said:
That is correct. SA and NA questions are asking for different things. SA (what would have to happen to trigger the conclusion) is left side of arrow and NA (just enough to guarantee the conclusion) is right side of arrow. AC may hav…
This is perfect for me thanks so much for the write up. The two reasons you give together certainly help me see why this answer should be struck out. Thanks a bunch
@Matthew524 said:
@Euthyphro you have committed a flaw in your reasoning. Just because we aren't in law school does not mean we do not have insight about the questions he asked.
lol and you made an unfounded assumption I never implied that we are …
This happened to me at first too. I found taking a break and reviewing the lessons helped. Say I got stuck on something, I would come back the next day and try it again.
Ah I see. So contrapositive is not a negation just the same logically equivalent statement. Thanks I will just memorize that All's negation as "Some Not". Thanks again