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Bijective function
Set
| $X,Y$ |
| $ f\in \mathrm{Bijective}(X,Y) $ |
| $ f\in \mathrm{Injective}(X,Y) $ |
| $ f\in \mathrm{Surjective}(X,Y) $ |
Discussion
Predicates
| $X\approx Y\equiv \mathrm{Bijective}(X,Y)\ne\emptyset$ |
We also write $X$ equinumerous $Y$.
| $X\preccurlyeq Y \equiv \exists (X'\subseteq Y).\ X'\approx X$ |
We also write $X$ smaller $Y$.
| $Y$ … countably infinite $\equiv \mathbb N\approx Y$ |
Parents
Requirements
