Question

What is the assumption needed to begin an indirect proof of the following statement?

“Cows do not have horns.”

Answer 1

Bulls do not have horns.

Bulls have horns.

Cows do not have horns.

Cows have horns.

Answer 2

There are many types of indirect proof.

Answer 3

If you're doing a proof by contradiction, you'd assume "Cows have horns" and the show that there is a contradiction.

Answer 4

Yeah, it was proof by contradiction, thanks!