Function
# Definition
Let $X, Y$ be Sets. Then a Function $X$ to $Y$ is a Relation $f \subset X \times Y$ such that for each $x \in X$, there exists a unique $y \in Y$ such that $(x, y) \in f$. We write $f: X \to Y$ and $f(x) := y$.
Search
Let $X, Y$ be Sets. Then a Function $X$ to $Y$ is a Relation $f \subset X \times Y$ such that for each $x \in X$, there exists a unique $y \in Y$ such that $(x, y) \in f$. We write $f: X \to Y$ and $f(x) := y$.