<leaf>

<leaf> encodes the leaves (terminal nodes) of a tree. 19.2 Trees
Modulenets — 19 Graphs, Networks, and Trees
AttributesIn addition to global attributes
valueprovides a pointer to a feature structure or other analytic element.
Status Required when applicable
Datatype 

<rng:ref name="data.pointer"/>
data.pointer
Values A valid identifier of a feature structure or other analytic element.
parentprovides the identifier of parent of a leaf.
Status Optional
Datatype 

<rng:ref name="data.pointer"/>
data.pointer
Values The identifier of the parent node.
followprovides an identifier of an element which this leaf follows.
Status Required when applicable
Datatype 

<rng:ref name="data.pointer"/>
data.pointer
Values The identifier of another intermediate node or leaf of the tree.
Note
If the tree is unordered or partially ordered, this attribute has the property of fixing the relative order of the leaf and the element which is the value of the attribute.
Used bytree
May contain
core: label
Declaration

<rng:element name="leaf">
<rng:ref name="att.global.attributes"/>
<rng:optional>
 <rng:attribute name="value">
  <rng:ref name="data.pointer"/>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:attribute name="parent">
  <rng:ref name="data.pointer"/>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:attribute name="follow">
  <rng:ref name="data.pointer"/>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:ref name="label"/>
</rng:optional>
</rng:element>
element leaf
{
   att.global.attributes,
   attribute value { data.pointer }?,
   attribute parent { data.pointer }?,
   attribute follow { data.pointer }?,
   label?
}
Example
<leaf xml:id="peri1" parent="#n1">
 <label>periscope</label>
</leaf>
Note
The in degree of a leaf is always 1, its out degree always 0.