Context-Free Tree Grammars are as Powerful as Context-Free Jungle Grammars

Frank Drewes, Joost Engelfriet
2015 Acta Cybernetica  
Jungles generalize trees by sharing subtrees and allowing garbage. It is shown that IO context-free tree grammars generate the same jungle languages as context-free jungle grammars. Also, they define the same subsets of any algebra.
doi:10.14232/actacyb.22.2.2015.9 fatcat:xs5uiparvrb3td43hpk4hlgh5m