Injectivity, Surjectivity, Bijectivity
QUESTION
Injectivity, Surjectivity, Bijectivity
Click to reveal answer ANSWER
A map $f : X \to Y$ is:
- **Surjective** (onto) if $f(X) := \{f(x) : x \in X\} = Y$.
- **Injective** (one-to-one) if $x_0 \neq x_1 \implies f(x_0) \neq f(x_1)$.
- **Bijective** if it is both surjective and injective.
Click to see question - ソースノート: chapter1.md
- カードID: injectivity-surjectivity-bijectivity
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