Hyper-AFLs and ET0L Systems
Per Ahlgren Christensen · DAIMI Report Series · 1974
This Paper deals with relations between substitutions and parallel rewriting in the sense of Lindenmayer-systems. We are especially interested in iterated substitution, which was introduced by Jan van Leeuwen and Arlo Salomaa, and which is a generalkation of the EOL- and the ETOL-system. In a natural way these iterated substitutions lead to the notion of a hyper-AFL, and it will be proved that the family of ETOL languages is the smallest hyper-AFL.