Insert a leaf with the given data into a tree:

Insert a subtree at any position:

Insert at several positions:

Use the operator form of TreeInsert:

Inserting an expression other than a Tree object is equivalent to inserting a leaf:

The expression x is inserted as the leaf :

Insert several subtrees using Splice:

Subtrees can be inserted, as well as replaced or deleted:

Construct a tree from the heads in an expression:

TreeInsert inserts a subtree into a tree:

This corresponds to inserting a subexpression into an expression:

Insert can insert subexpressions directly:

For a tree with n children, there are n+1 available positions to insert a new child:

If pos is not a list, pos and {pos} are equivalent specifications:

TreeInsert inserts the new subtree repeatedly if a position is mentioned repeatedly:

TreeInsert can use the lists of positions returned by TreePosition:

These are the subtrees returned by TreeExtract:

TreeInsert[tree,new,{p₁,p₂,…}] treats {p₁,p₂,…} as a list of individual position specifications if all the p_i are lists:

For {{1,2},{3,4}}, the new subtree is inserted at positions {1,2} and {3,4}:

If any p_i is not a list, {p₁,p₂,…} is treated as a list of part specifications:

For {{{1,2},{3,4}}}, the new subtree is inserted at parts 3 and 4 of parts 1 and 2:

TreeInsert[tree,new,{}] does not insert any subtrees because the list of positions is empty:

Subtrees cannot be inserted at the root:

Subtrees cannot be inserted into a leaf:

For an inner node with no children, a child can be inserted at position 1: