Supply the missing premise that makes the conclusion follow logically:P: X → YP: ?C: X does not exist

Kathy3755 December 11, 2017

Please explain why (D) is incorrect

I understand why "Y" does not exist but why would (Not y - > not x) be incorrect Please explain, thank you!

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Kathy3755 December 12, 2017

Not sure I alerted the instructor

Halle-Diaz June 7, 2018

I also am unsure on this.

Christopher June 8, 2018

Not y ==> not x is the correct contrapositive for x ==> y, but it won't lead you to the conclusion that X does not exist. You need to introduce more information to reach that conclusion, such as Y does not exist.

Does that help?

edith-baez June 4, 2021

I got this wrong and I was thinking about it. I think that the contrapositive also leaves it open that Y can exist if X exists. I hope I do not make this mistake again.