A4 - Hints, Tips, and FAQ
=========================

Q: 3(a) and 3(b) don't make sense. Is there a typo?
A: Though, given my track record, I completely understand why you would
   think this, they are *not* typos. 

Q: If I have two formulas down to the same format, but with different
   propositional variables, are they logically equivalent?
A: Generally speaking, no. Consider two formulas A /\ B  and A /\ C. While 
   they have the same format, they are not logically equivalent *unless* 
   you happen to know that B and C are logically equivalent. For instance 
   the truth assignment A = 1, B = 1, C = 0 results in different values
   for the two formulas.

Hint: Particularly for the confusing ones in question three, you may find
   that a logical equivalence or two that isn't in our given laws might
   be useful. For instance, it might help if you could claim that 
   P \/ (Q /\ P) LEQV P. (Speaking hypothetically, of course.)

Tip: You must prove any logical equivalence you use that we did not discuss
   in class. This can be tricky. If you find yourself in a position where 
   the equivalence laws we've given you aren't quite getting you where you 
   need to be, you might want to go back to the alternate definitions of 
   what it means for two formulas to be logically equivalent.