m-ary trees; the level of a node and the height of a tree
A rooted tree is called an m-ary tree iff every internal vertex has no
It is called a full m-ary tree iff every internal vertex has exactly m
An m-ary tree with m=2 is called a binary tree.
An ordered rooted tree is a rooted tree where the children of each
internal vertex are ordered (“1st child”, “2nd child”, … or
“the left child” and “the right child” in a binary tree).
The level of a vertex in a rooted tree is the length of the unique path
from the root to this vertex.
The height of a rooted tree is the maximum of the levels of vertices.