\input zb-basic
\input zb-ioport
\iteman{io-port 03902066}
\itemau{Yokomori, Takashi; Wood, Derick}
\itemti{An inverse homomorphic characterization of full principal AFL.}
\itemso{Inf. Sci. 33, 209-215 (1984).}
\itemab
In spite of the quite laborious proof, the main result of this paper acquires a concise and elegant form: Let ${\cal L}$ be a full principal AFL closed under context-free substitution. Then there is a fixed language $L\sb 0$ in ${\cal L}$ such that for each L in ${\cal L}$ there exist a weak coding h and a homomorphism g such that $L=hg\sp{-1}(L\sb 0).$ An immediate corollary shows that there is a fixed ETOL language $L\sb 0$ such that for each ETOL language L there exist h and g as above such that $L=hg\sp{-1}(L\sb 0)$.
\itemrv{R.Andonie}
\itemcc{}
\itemut{full principal AFL; ETOL language}
\itemli{doi:10.1016/0020-0255(84)90029-X}
\end