Its characteristics are: there is a progressive relationship between words and words, and there is a node word that can be derived from another node word, and it can be deduced either forward or backward.
It is characterized by a progressive relationship between words and words, and one node word can be derived from another node word, which can be pushed back and backward.
The characteristics of the word are: the word and word are progressive, one node word can be deduced another node word, both forward and reversible.<br>