Surjection/Examples/Arbitrary Finite Set

Example of Surjection

Let $S$ and $T$ be sets such that:

 $\displaystyle S$ $=$ $\displaystyle \set {a, b, c}$ $\displaystyle T$ $=$ $\displaystyle \set {x, y}$

Let $f: S \to T$ be the mapping defined as:

 $\displaystyle \map f a$ $=$ $\displaystyle x$ $\displaystyle \map f b$ $=$ $\displaystyle x$ $\displaystyle \map f c$ $=$ $\displaystyle y$

Then $f$ is a surjection.