<!ENTITY c "<computeroutput>C</computeroutput>">
<!ENTITY defsystem "<application>defsystem</application>">
<!ENTITY bookinfo SYSTEM "bookinfo.sgml">
+<!ENTITY preface SYSTEM "preface.sgml">
<!ENTITY intro SYSTEM "intro.sgml">
<!ENTITY notes SYSTEM "notes.sgml">
<!ENTITY ref SYSTEM "ref.sgml">
+<!ENTITY appendix SYSTEM "appendex.sgml">
+<!ENTITY glossary SYSTEM "glossary.sgml">
]>
<book>
&bookinfo;
+&preface;
&intro;
¬es;
&ref;
+&appendix;
+&glossary;
</book>