\input zb-basic
\input zb-ioport
\iteman{io-port 70309891}
\itemau{Apt, Krzysztof R.; Gabbrielli, Maurizio}
\itemti{Declarative interpretations reconsidered}
\itemso{ICLP, 74-89 (1994).}
\itemcc{}
\itemut{}
\itemli{}
\end