The Nature of Infinity: An Introduction to Georg Cantor's Ideas

Minor typo I think:<p><pre><code> Proof of the Countability of the Rational numbers ℚ Let us first propose that the set of rational numbers ℚ is countable. To prove this assertion, let us arrange all the rational numbers (ratios of natural numbers) in an infinite table as such: 1&#x2F;1 1&#x2F;2 1&#x2F;3 1&#x2F;4 1&#x2F;5 ... 2&#x2F;1 2&#x2F;2 2&#x2F;3 2&#x2F;4 2&#x2F;5 ... 3&#x2F;1 3&#x2F;2 3&#x2F;3 3&#x2F;4 3&#x2F;5 ... 4&#x2F;1 4&#x2F;2 4&#x2F;3 4&#x2F;4 4&#x2F;5 ... 5&#x2F;1 5&#x2F;2 5&#x2F;3 5&#x2F;4 6&#x2F;5 ... ... ... ... ... ... </code></pre> The last fraction should be 5&#x2F;5, no? Not 6&#x2F;5.