What Makes a Pairing Count?
Diagonalization, Baire category, and measure theory all show the same thing: an N-indexed presentation does not exhaust the admitted field of total binary profiles. So the diagonal witness is not the source of the result; it is one certificate.
The prior issue is what makes a pairing verdict-bearing.
For N and the evens, direct overlap leaves odd residue in N. The doubling map pairs every natural with an even. The sets do not change; only the authorized comparison relation does.
Cardinality resolves this by rule: one completed total bijection over the declared domains overrides containment, residue, order, and generative difference.
Cantor’s theorem then proves non-exhaustion inside that prior protocol.
The theorem proves non-exhaustion; cardinality classifies it. Why call that a discovery of magnitude rather than a result of the chosen comparison rule?