`<tree>` | encodes a tree, which is made up of a root, internal nodes, leaves, and arcs from root to leaves.

Attributes:

`label` | gives a label for a tree.
| Datatype: CDATA
| Values: A character string.
| Default: #IMPLIED

`arity` | gives the maximum number of children of the root and internal nodes of the tree.
| Datatype: NUMBER
| Values: A nonnegative integer.
| Default: #IMPLIED
`ord` | indicates whether or not the tree is ordered, or if it is partially ordered.
| Datatype: (Y | N | partial)

Legal values:

`Y` | 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.
`N` | indicates that all of the branching nodes of the tree are unordered.

| Default: Y
`order` | gives the order of the tree, i.e., the number of its nodes.
| Datatype: NUMBER
| Values: A nonnegative integer.
| Default: #IMPLIED
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.

Example

    <tree n='ex2' ord=partial arity=2 order=13>
       <root  label='/'  id=div1   ord=Y             children='plu1 exp1'>
       <iNode label='+'  id=plu1   ord=N parent=div1 children='exp2 exp3'>
       <iNode label='**' id=exp1   ord=Y parent=div1 children='plu2 num2.3'>
       <iNode label='**' id=exp2   ord=Y parent=plu1 children='vara1 num2.1'>
       <iNode label='**' id=exp3   ord=Y parent=plu1 children='varb1 num2.2'>
       <iNode label='+'  id=plu2   ord=N parent=exp1 children='vara2 varb2'>
       <leaf  label='a'  id=vara1        parent=exp2>
       <leaf  label='2'  id=num2.1       parent=exp2>
       <leaf  label='b'  id=varb1        parent=exp3>
       <leaf  label='2'  id=num2.2       parent=exp3>
       <leaf  label='a'  id=vara2        parent=plu2>
       <leaf  label='b'  id=varb2        parent=plu2>
       <leaf  label='2'  id=num2.3       parent=exp1>
       </tree>

Tagsetadditional tag set for graphs, networks, and trees
Classchunk [and indirectly also:] common
Filename`teinet2`
Content: 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.
Parentsadd argument body castList corr div div0 div1 div2 div3 div4 div5 div6 div7 epigraph epilogue equiv forest item metDecl note performance prologue q quote remarks set sic stage view
ChildreniNode leaf root
Declaration

    <!ELEMENT tree          - -  ((leaf | iNode)*, root, (leaf |
                                 iNode)*)                           >
    <!ATTLIST tree               %a.global
              label              CDATA               #IMPLIED
              arity              NUMBER              #IMPLIED
              ord                (Y | N | partial)   Y
              order              NUMBER              #IMPLIED       >

See 21.2

Back to index