Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.



Tautology Proof Question
Posted:
Mar 19, 2012 4:51 AM


Hello guys,
While studying, I've passed through this proof (in the class notes):
Example: Proof that: ( (p v q) ^ (p > r) ^ (q > r) ) > r is a tautology?
The solution is: ( (p v q) ^ (¬p v r) ^ (¬q v r) ) > r ( (p ^ ¬p) v (r ^ q) ^ (¬q v r) ) > r (F v (q ^ ¬q) v r) > r r > r ¬r v r .: T
Actually I can't understand the steps, am not sure if the notes are wellwritten here, but I'll appreciate any help in explaining the proof.
Regards, ASH



