# ML Wiki

## Trees

A Tree $T$ is a Graph that:

Trees can be

• Ranked or Unranked
• Ordered or Unordered

### Ranked Trees

A tree is ranked if you know in advance how many children a node has

A tree is unranked if you don't know in advance the number of children

### Ordered Trees

A tree is ordered if the order of children matters

For example,

## Sources

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