Sufficient and necessary / denying and affirming

SashaSevy

I just want to confirm my understanding on this.

Are these true?

If sufficient fails then no valid conclusions about the necessary condition, but if sufficient satisfied or affirmed then it triggers necessary, hence we can have a valid conclusion.
If necessary fails then it would trigger the sufficient, hence we can have a valid conclusion, but if necessary satisfied or affirmed then no valid conclusion.

and also whats the best way to memorize this? lol

annabellouise.jones

Yes, you got it! Sufficient satisfied -> affirm necessary condition. Necessary failed -> fail sufficient condition. Maybe you can remember it by what triggers the rule - use the acronym SS (sufficient satisfied) is good and then necessary triggers the rule in the opposite way (failed) so NF good also.