This paper continues the research (started in ) on elementary DOL systems. In particular we provide an alternative (and simpler than the one presented in ) proof that the DOL sequence equivalence problem is decidable.
Ehrenfeucht, Andrzej and Rozenberg, Grzegorz, "Elementary Homomorphisms and a Solution of the DOL Sequence Equivalence Problem ; CU-CS-115-77" (1977). Computer Science Technical Reports. 113.