3.2 proving contrapositive

[David Cantrell]

Hi Sibi,

In 3.2 you mention several times that you will prove the contrapositive. Did you mean proof by contradiction instead? For example, in question 7 there is no implication.

I'm working through 3.2 right now and adding a couple alternate proofs, so I can change those from contrapositive if you'd like. Just let me know. Thanks.

Dave

[Sibi Prabakaran]

Please, change them and send me a PR!

[Sibi Prabakaran]

Can this issue be closed ?