Definition:Class Surjection

Definition
Let $A$ and $B$ be classes.

Let $f: A \to B$ be a class mapping from $A$ to $B$.

Then $f$ is said to be a class surjection :
 * $\forall y \in B: \exists x \in A: \map f x = y$

Also see

 * Definition:Class Injection
 * Definition:Class Bijection