<p>An "Ordered Tree Type" is a data type that defines the properties of data structures that represent ordered trees.
An ordered tree is a tree where the children of every node are ordered, that is, there is a first child, second child, third child, etc.
Typically a type specification for an ordered tree will include the comparison operator (such as <b>lt</b> or <b>gt</b>) that is used to order the nodes.
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