Algorithm of a tree (Sextuple Crystalline Poetry)

(A two line image poem, often with a title, in which euphony is the key factor. Each line may have 8 or 9 syllables to make a total of seventeen)

A free tree is never rooted, 

Infinite complete binary tree.

A finger tree has internal nodes and

Each one in this tree has child nodes.

And their connection is a walk, 

Parents and children walking the tree.

Nodes without children are called leaves, 

While roots are leaves for the finger trees.

Very intelligent are the words tree, 

Trees-no one-to-one correspondence, 

Adaptive merging operation, 

Implementing finger search trees.