I had a question regarding tautologies. I have three different compound wff's for P and Q (P ^ Q) (P -> Q) ((P ^ (Q -> P)). For all of these, I'm supposed to construct compound wff's for all of these so that they'll be tautologies. I'm not really sure how to do that. I've tried a lot of randome statements to see if I can get them to work, but I haven't had any luck. Is there a specific strategy to doing this? Any help would be appreciated.