\input zb-basic
\input zb-ioport
\iteman{io-port 50285547}
\itemau{Ayala-Rinc\'on, Mauricio; Mu\~noz, C\'esar}
\itemti{Explicit substitions and all that}
\itemso{Revista Colombiana de Computaci\'on 1, No. 1, 47-71 (2000).}
\itemcc{}
\itemut{}
\itemli{http://www.unab.edu.co/editorialunab/revistas/rcc/pdfs/r11\_art3\_c.pdf}
\end