I was trying to prove this statement is a tautology without using truth tables. Something doesn't add it here as I keep getting stuck. Take a look please!
For statements, P, Q and R prove that that the statement $$ [(P \implies Q) \implies R] \lor [\neg P \lor Q]$$
It is possible to do this without truth tables right? Here is what I have so far! :)
The statement $(P \implies Q)$ can be collapsed into $(\neg P \lor Q)$. So we can replace the phrase $[(P \implies Q) \implies R]$ with $(\neg P \lor Q) \implies R$. Again, we can collapse that expression and get $(P \land \neg Q) \lor R)$. From here I am not sure where to go. There isn't even an $R$ in the expression $[\neg P \lor Q]$ ! Help would be greatly appreciated! Thank you :)