MAT102 Tutorial W5B

102_F2025_Tutorial5.pdf

• 1
  • Show that $|\mathcal{P}(\mathbb{N}\times \mathbb{N})|=|\{f:\mathbb{N}\to \mathbb{N}\}|$
  • Let $f:\mathcal{P}(\mathbb{N}\times \mathbb{N})\to \{f:\mathbb{N}\to \mathbb{N}\}$
  • $|\mathcal{P}(A)|=2^n-1$
  • $f(x)=f(y)$