- #1
Doom of Doom
- 86
- 0
So, the task is to prove: Every infinite set has a infinite countable subset.
2. A set [tex]S[/tex] is countable if there exists a bijection [tex]\phi: \mathbb{N}\rightarrow X[/tex]
2. A set [tex]S[/tex] is countable if there exists a bijection [tex]\phi: \mathbb{N}\rightarrow X[/tex]