4 ms·

The "therefore" is not quite right. You have shown that that the original assumption leads to a contradiction and so doesn't hold.

• hgsgm 4y ago
  That's incorrect. The assumption was that there was a 1:1 (injective) mapping, and the proof was that it (regardless of it's exact value) wasn't onto (surjective) and so isn't bijective.
  • sorokod 4y ago
    True when replacing "1 to 1 mapping" with "1:1 injective mapping"