<tree>

<tree> (tree) encodes a tree, which is made up of a root, internal nodes, leaves, and arcs from root to leaves. [20.2 Trees]
Module nets — Graphs, Networks, and Trees
Attributes
arity⚓︎ gives the maximum number of children of the root and internal nodes of the tree.
Status Optional
Datatype teidata.count
ord⚓︎ (ordered) indicates whether or not the tree is ordered, or if it is partially ordered.
Status Required
Datatype teidata.enumerated
Legal values are:
true
indicates that all of the branching nodes of the tree are ordered.
partial
indicates that some of the branching nodes of the tree are ordered and some are unordered.
false
indicates that all of the branching nodes of the tree are unordered.
order⚓︎ gives the order of the tree, i.e., the number of its nodes.
Status Optional
Datatype teidata.count
Note

The size of a tree is always one less than its order, hence there is no need for both a size and order attribute.
Member of
model.divPart model.standOffPart
Contained by
core: item note q quote said stage textLang
drama: castList epilogue performance prologue set view
figures: cell figure
header: change handNote licence scriptNote
linking: standOff
msdescription: accMat acquisition additions collation condition custEvent decoNote filiation foliation layout musicNotation origin provenance signatures source summary support surrogates typeNote
namesdates: occupation
nets: forest
tagdocs: specGrp
textcrit: lem rdg
textstructure: argument body div div1 div2 div3 div4 div5 div6 div7 epigraph postscript
transcr: metamark
May contain
core: label
nets: iNode leaf root
Note

A root, and zero or more internal nodes and leaves, but if there is an internal node, there must also be at least one leaf.
Example
<tree n="ex2" arity="2" ord="partial"
 order="13">
 <root xml:id="G-div1"
  children="#G-plu1 #G-exp1" ord="true">
  <label>/</label>
 </root>
 <iNode xml:id="G-plu1"
  children="#G-exp2 #G-exp3" parent="#G-div1" ord="false">
  <label>+</label>
 </iNode>
 <iNode xml:id="G-exp1"
  children="#G-plu2 #G-num2.3" parent="#G-div1" ord="true">
  <label>**</label>
 </iNode>
 <iNode xml:id="G-exp2"
  children="#G-vara1 #G-num2.1" parent="#G-plu1" ord="true">
  <label>**</label>
 </iNode>
 <iNode xml:id="G-exp3"
  children="#G-varb1 #G-num2.2" parent="#G-plu1" ord="true">
  <label>**</label>
 </iNode>
 <iNode xml:id="G-plu2"
  children="#G-vara2 #G-varb2" parent="#G-exp1" ord="false">
  <label>+</label>
 </iNode>
 <leaf xml:id="G-vara1" parent="#G-exp2">
  <label>a</label>
 </leaf>
 <leaf xml:id="G-num2.1" parent="#G-exp2">
  <label>2</label>
 </leaf>
 <leaf xml:id="G-varb1" parent="#G-exp3">
  <label>b</label>
 </leaf>
 <leaf xml:id="G-num2.2" parent="#G-exp3">
  <label>2</label>
 </leaf>
 <leaf xml:id="G-vara2" parent="#G-plu2">
  <label>a</label>
 </leaf>
 <leaf xml:id="G-varb2" parent="#G-plu2">
  <label>b</label>
 </leaf>
 <leaf xml:id="G-num2.3" parent="#G-exp1">
  <label>2</label>
 </leaf>
</tree>
Content model 
<content>
 <sequence>
  <elementRef key="label" minOccurs="0"/>
  <sequence>
   <alternate minOccurs="0"
    maxOccurs="unbounded">
    <elementRef key="leaf"/>
    <elementRef key="iNode"/>
   </alternate>
   <elementRef key="root"/>
   <alternate minOccurs="0"
    maxOccurs="unbounded">
    <elementRef key="leaf"/>
    <elementRef key="iNode"/>
   </alternate>
  </sequence>
 </sequence>
</content>
Schema Declaration 
<rng:element name="tree">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.rendition.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:ref name="att.global.source.attributes"/>
 <rng:optional>
  <rng:attribute name="arity">
   <rng:ref name="teidata.count"/>
  </rng:attribute>
 </rng:optional>
 <rng:attribute name="ord">
  <rng:choice>
   <rng:value>true</rng:value>
   <rng:value>partial</rng:value>
   <rng:value>false</rng:value>
  </rng:choice>
 </rng:attribute>
 <rng:optional>
  <rng:attribute name="order">
   <rng:ref name="teidata.count"/>
  </rng:attribute>
 </rng:optional>
 <rng:group>
  <rng:optional>
   <rng:ref name="label"/>
  </rng:optional>
  <rng:group>
   <rng:zeroOrMore>
    <rng:choice>
     <rng:ref name="leaf"/>
     <rng:ref name="iNode"/>
    </rng:choice>
   </rng:zeroOrMore>
   <rng:ref name="root"/>
   <rng:zeroOrMore>
    <rng:choice>
     <rng:ref name="leaf"/>
     <rng:ref name="iNode"/>
    </rng:choice>
   </rng:zeroOrMore>
  </rng:group>
 </rng:group>
</rng:element>
element tree
{
   att.global.attributes,
   att.global.rendition.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   att.global.responsibility.attributes,
   att.global.source.attributes,
   attribute arity { teidata.count }?,
   attribute ord { "true" | "partial" | "false" },
   attribute order { teidata.count }?,
   ( label?, ( ( leaf | iNode )*, root, ( leaf | iNode )* ) )
}