Uncountability
QUESTION
Uncountability
Click to reveal answer ANSWER
A set $X$ is **uncountable** if it is not the image of $\mathbb{N}$ ($\text{card } X > \aleph_0$).
- The set of real numbers $\mathbb{R}$ is uncountable (Proposition I.5.7). Its cardinality is denoted by $\mathfrak{c}$ (continuum).
Click to see question - ソースノート: chapter1.md
- カードID: uncountability
- 状態: active