There's one of these pseudo-proofs for "1 = 0", too; it basically goes like this: 0 = 0 + 0 + 0 + ... = (1 - 1) + (1 - 1) + ..."; using associativity, "(1 - 1) + (1 - 1) + ... = 1 + (-1 + 1) + (-1 + 1) + ... = 1 + 0 + 0 + ... = 1". What's invalid here is that the law of associativity does not hold for infinite sums that aren't absolutely convergent.   00:12 25 Jun 2003 (UTC)