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!

Quote:

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Originally Posted by Nora314

Hi everyone!
Is the following a tautology:
[(r -> q) -> p] ↔ [r -> (q -> p)]

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Say . SO?

The first is .

The second is