# Definition:Rooted Tree/Root Node

< Definition:Rooted Tree(Redirected from Definition:Root Node)

*This page is about the root node of a rooted tree. For other uses, see Definition:Root.*

## Definition

Let $T$ be a rooted tree.

The **root node** of $T$ is the node of $T$ which is distinguished from the others by being the ancestor node of every node of $T$.

## Also known as

The **root node** of a rooted tree can be referred to as just the **root**.

## Sources

- 1996: H. Jerome Keisler and Joel Robbin:
*Mathematical Logic and Computability*... (previous) ... (next): $\S 1.7$: Tableaus