Finite and Infinite
QUESTION
Finite and Infinite
Click to reveal answer ANSWER
- A set $X$ is **finite** if every injection $f : X \to X$ is a surjection. Otherwise it is **infinite**.
- $\text{card } \emptyset = 0$.
Click to see question - ソースノート: chapter1.md
- カードID: finite-and-infinite
- 状態: active