Is the following a tautology?

Hi everyone!

On my exam there is always a question like this:

Is the following a tautology:

[(r -> q) -> p] ↔ [r -> (q -> p)]

I know how to solve this pretty easy by using a truth table or by just thinking a bit about the logic behind the statement. I was just wondering, is there some easier way to do this? I know about logical equivalence identities, but I find them difficult to apply to these kind of problems.

Thanks to anyone who reads this!

Re: Is the following a tautology?

Quote:

Originally Posted by

**Nora314** Hi everyone!

Is the following a tautology:

[(r -> q) -> p] ↔ [r -> (q -> p)]

Say . SO?

The first is .

The second is