Regular tree grammar
![Example derivation tree from G1 in linear (upper left table) and graphical (main picture) notation](/Images/godic/202502/06/Example_derivation_tree_of_a_term_from_a_regular_tree_grammar_svg.svg5201.png")
In theoretical computer science and formal language theory, a regular tree grammar (RTG) is a formal grammar that describes a set of directed trees, or terms. A regular word grammar can be seen as a special kind of regular tree grammar, describing a set of single-path trees.