Note: In the absence of actual logical proofs that the IPU (Invisible Pink Unicorn, an omnipotent, omniscient entity at the center of the universe) does exist, placeholder illogical proofs that Ipu does exist have been inserted. Feel free to come up with some real ones. * Statement 1: IPU Does Exist. * Statement 2: Both statement 1 and statement 2 are false. If statement 2 is true, then statement 2 is false. This is impossible. On the other hand, if statement 2 is false, statement 1 and statement 2 are not both false, so statement 1 is true. Therefore, IPU Does Exist. ---- Alternately: The statement "if 0, then 1" logically means that if anything false is true, everything is true. All that is needed at this point is to prove that something that is false is really true. I forget the one with the factoring and divide by zero trick with variables ... * Suppose '''a=b'''. Multiply through by '''a''' and subtract '''b*b''' from both sides giving '''a*a-b*b = a*b-b*b'''. Factor each side to give '''(a+b)*(a-b) = b*(a-b)'''. Now we can divide through by '''(a-b)''' giving '''a+b=b'''. Since '''a=b''' we have '''2b=b''' and dividing by '''b''' gives '''2=1''' ... but here's the one I do remember: Start with -1=-1. This is obviously true (I probably shouldn't say that because somebody'll make a page stating that it isn't, but I'll start with it being true). Take the square root of both sides, sqrt(-1)=sqrt(-1). Turn each -1 into a fraction, sqrt(-1/1) = sqrt(-1/1). Move the negative sign on the right to the denominator. sqrt(-1/1) = sqrt(1/-1). Separate the square root to be: sqrt(-1)/sqrt(1) = sqrt(1)/sqrt(-1). Cross multiply to get sqrt(-1)*sqrt(-1) = sqrt(1)*sqrt(1). Simplify to get -1=1. This proves that something false is true, this IPU exists. That deliberately ignores the imaginary component ''i'' == sqrt(-1); this pointless {although the subtext is about as obvious as a pink unicorn} discussion is mute as when no evidence is available it is simply indeterminate (think of 0/0 or QuantumTheory) in the case of a pink unicorn supposedly at the center of the universe the only way to verify this would be to travel there and the explore the indeterminacy of whatever event horizon it might be hiding behind. At least other discussions that rage about does xxyyzz exist usually have a point of focus as to why xxyyzz exists, some evidence (even if some would dispute it) as to its existence and just what its existence would mean without having to resort to mathematical sleight of hands :) --AndrewMcMeikan There is also the theory that imaginary numbers are more aptly named than you might think -- mathematicians thought them up when they realized this paradox to keep the hordes of smartass kids from running up to them and going "everything you believe in is false, nyah nyah nyah!" -- MattBehrens ;) If only everything was one or the other. True or false. While some things certainly are true or false a compound self referential statement, such as this one, does not have to be --amc ''You're right that not all propositions are true or false. Some are arbitrary (i.e. meaningless). -- DanHankins'' ---- IPU exists because I believe it exists. I can't be possibly wrong. Authority X also beliefs IPU exists and ''he'' cannot be possibly wrong, since he has even written a book on it. Which sold more copies than K&R's ''The C programming language'', so there you go. What? You expected actual reasoning? Logically valid reasoning? That's so 19th century. Nowadays, we don't reason, we seek contact with our inner selves. So stop arguing that IPU doesn't exist. You are hurting my feelings. -- StephanHouben ---- CategoryLogic CategoryWhimsy CategoryProof