Delete the second child of a tree:

Delete a subtree at any position:

Delete subtrees at several positions:

Use the operator form of TreeDelete:

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

Construct a tree from the heads in an expression:

TreeDelete deletes a subtree of a tree:

This corresponds to deleting a subexpression of an expression:

Delete can delete subexpressions directly:

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

Deleting position {} deletes the whole tree:

TreeDelete ignores repeated positions:

TreeDelete can use the lists of positions returned by TreePosition:

These are the subtrees returned by TreeExtract:

TreeDelete[tree,{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 subtrees at positions {1,2} and {3,4} are deleted:

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

For {{{1,2},{3,4}}}, parts 3 and 4 of parts 1 and 2 are deleted:

TreeDelete[tree,{}] does not delete any subtrees because the list of positions is empty:

TreeDelete[tree,{{}}] deletes position {}, which corresponds to the whole tree: