Assertion: tree | /r/HasProperty | empty
Facets:
value: with a tree
type: OTHER
value: with no nodes
type: OTHER
value: always
type: DEGREE
value: possibly
type: DEGREE
Source sentences:
text: A tree can be empty with no nodes or a tree is a structure consisting of one node called the root and zero or one or more subtrees.
text: Recursively, as a data type a tree is defined as a value (of some data type, possibly empty), together with a list of trees (possibly an empty list), the subtrees of its children; symbolically:
text: instead being represented by a forest of zero trees), or allow trees to be empty, in which case the list of children can be of fixed size (branching factor, especially 2 or "binary"), if desired.
text: For example, rather than an empty tree, one may have a null reference: a tree is always non-empty, but a reference to a tree may be null.
text: Depending on definition, a tree may be required to have a root node (in which case all trees are non-empty), or may be allowed to be empty, in which case it does not necessarily have a root node.
text: A tree can be empty with no nodes or a tree is a structure consisting of one node called the root and zero or one or more subtrees.