[Suggestions] Theorem 2.6 (cantor's theorem)

[hileamlakB]

In the computation and representation chapter, there is some confusing naming that could be improved. For instance in lemma 2.8

F is used to mean a set of functions mapping natural numbers to 1 or 0. But F was previously used to mean, a mapping from real numbers to a set of binary strings (towards contradiction), in the same discussion a few lines above.

Thus in lemma 2.8 and 2.9, it would make sense to stick with X, which was described in the second picture.

Thank you!