\begin{definition}[Definition:Labeled Tree]
A '''labeled tree''' is a finite rooted tree in which each node has attached to it a '''label'''.
These '''labels''' may be any symbol or other object that one can think of, but usually consist of one letter or symbol.
{{expand|A picture like [http://mathworld.wolfram.com/images/eps-gif/PrueferCode_700.gif this], exemplifying the below}}
The parent function is usually depicted by placing the ancestor above the child and connecting them with a line.
The various children of a node may also be considered to be in a particular order.
This is usually depicted by placing them in a left-to-right order.
Because of the intuitive clarity of these relations, '''labeled trees''' may be considered collations as basic as strings are.
However, because of the space limitations that most printed media have to take into account, it is usual that one quickly resorts to representing trees by strings in one way or another.
Category:Definitions/Formal Systems
\end{definition}