Hey guys these are the problems that I have a hard time doing. I get confused with how the laws work sometimes. If you guys could help me that would be awesome.

Using the laws of sentential logic and the rules of inference prove the target formulas using the given WFFs:

1. Given (a →b) anda →c), andaprove (b∧c).

2. Given (a∨b), ¬ (a∧b), and ¬b, provea.

3. Given (a∧b) prove (a∨b).

I am also having some issues with this problem as well:

Give an example of a logical formula involving the atomic statements a, b, c, and d that is always true regardless of the value of these four atomic statements.