Extend the leaves of a tree:

Build a tree from an expression:

Build a tree by adding a level of children to a leaf:

Specify children as an association:

Build a leaf with no child:

Build a non-leaf with no child:

Add leaves:

Extend the leaves of a tree:

Build a tree with multiple levels:

Apply a function to the data in addition to extending the tree:

Specify the number of additional levels:

Repeatedly apply operators until no more levels are added:

Build a tree without evaluating intermediate results:

Specify children as an association:

Create a tree of life:

Create a tree of descendants:

Create a tree from the hierarchy of files in a directory:

Create a tree of terms in a linear recurrence:

Compute the terms of the linear recurrence:

Define a function that converts a TextElement object to a tree:

Define a function that yields the child elements of a TextElement:

Define a function that extracts the "GrammaticalUnit" from a TextElement:

Convert TextElement to a tree:

Create a tree of permutations:

Create a Calkin–Wilf tree:

Create a Stern–Brocot tree:

NestList gives a list of the results of successive applications of an operator f to an expression:

NestTree gives a tree of the results of successive applications of an operator f to an expression:

NestTree applies subsequent operators to each element of a list:

NestTree[f,expr,…] constructs a tree starting from the expression expr if expr is not a tree:

This is equivalent to NestTree[f,Tree[expr,None],…]:

If f does not return {…}, <|…|>, Hold[…] or None, NestTree[f,tree,…] is equivalent to NestTree[List@*f,tree,…]:

NestTree[f,Tree[expr,None],0] gives Tree[expr,None]:

NestTree[f,Tree[expr,None]] gives Tree[expr,None] if f[expr] gives None:

NestTree[f,Tree[expr,None]] gives Tree[expr,{…}] if f[expr] gives {…} or Hold[…]:

This is true even if f[expr] gives {} or Hold[]:

NestTree successively applies an operator f until the maximum level is reached or f returns None, {}, <||> or Hold[]:

NestTree[f,Tree[expr,None],n,h] gives the tree with data h[expr] and children NestTree[f,Tree[expr_i,None],n-1,h], where f[expr] gives {expr₁,expr₂,…}:

NestTree[TreeChildren,Tree[tree,None],Infinity,TreeData] is equivalent to tree:

NestGraph applies an operator to each vertex in a graph:

NestTree applies an operator to each leaf in a tree:

Imitate the output of CompleteKaryTree using NestTree:

Convert the tree to an actual Graph object:

Generate a tree containing random integers from 0 to 10 and between 1 and 3 children for internal subtrees:

Use RandomTree to generate a random tree of a certain size:

NestTree[f,tree] applies the function to the leaves' data:

To apply the function directly to the tree itself, use Tree[tree,None]:

Construct a tree of subdivisions of a geological period:

Construct a tree with levels giving the triangles in the 0- through 3-step Sierpiński triangles:

Obtain the 3-step Sierpiński triangle from this tree:

Construct a tree with levels giving the intervals in the 0- through 3-step Cantor sets:

Obtain the 3-step Cantor set from this tree: