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Surjective function
Set
| context | $X,Y$ |
| definiendum | $ f\in \mathrm{Surjective}(X,Y) $ |
| context | $ f:X\to Y $ |
| postulate | $ \text{im}(f)=Y $ |
Discussion
A function can only be or not be surjective w.r.t. to a stated codomain. A function is always surjective w.r.t. it's own image. See Function for further discussion.
Predicates
| predicate | $Y$ … countable $\equiv \mathrm{Surjective}(\mathbb{N},Y)\neq\emptyset$ |
Parents
Subset of
Context
