----------------------------------- xthexder Tue Jan 10, 2012 8:15 pm Round 3 Question 5 Sample Case? ----------------------------------- I didn't participate in this round, but going over the questions after, I noticed this in the sample test case: ((a ^ b) v (c ^ ~c)) is supposedly a tautology? I'm confused because as I see it, it is not a tautology, but no-one else seems to have said anything. What am I missing? ((a ^ b) v (c ^ ~c)) = ((a and b) or (c and ~c)) = ((a and b) or (false)) = (a and b) if a or b == false, then it's false. Don't tell me c is some tri-state variable... -xthexder ----------------------------------- Tony Tue Jan 10, 2012 9:42 pm RE:Round 3 Question 5 Sample Case? ----------------------------------- We actually caught that mistake during the contest; there was a notice put up. The sample was supposed to read [code] ((a ^ b) v ~(c ^ ~c)) [/code] Not sure why the archived version of the sample is reverted to the wrong copy...