% Example of a document instance marked up with gellmu
\documenttype[hack.dtd]{hack}
\title{Example document for \acro{SGML} processing}
\para
\bold{Abstract}\br
This document illustrates a simple \acro{SGML} document type.
It should be easy to write processors that can handle this document.

\section
\title{This document as an \acro{SGML} instance}
\para
The first \acro{SGML} file in the "hack" series was an example
of a complete document.  In this context \emph{complete} means
that the text file containing the document instance also holds the
\bold{document type definition} for the instance.
\para
More common practice is for the document type definition to reside in
a \begin{link}\url{hackdtd.txt}\linktext{separate text file}\end{link}
from the instance.  The file containing the document type definition
is referenced through the \bold{document type declaration},
which is the \code{DOCTYPE} container at or near the beginning
of the instance.

\section
\title{
Processing generalities
}
\para
In translating an \acro{SGML} document many steps are
obvious.
\para
In particular, for translation from one document type to another,
often many things can be translated element-wise.
\para
Sometimes, however, it is necessary to descend recursively into
an element.

\section
\title{
An example where recursive descent is needed
}
\para
For the task of translating this document type to \acro{HTML}
the \emph{link} element provides an example where element-wise
translation will not work.