diff -r f85386e8acdf -r 90568836340a doc-src/TutorialI/Documents/document/Documents.tex
--- a/doc-src/TutorialI/Documents/document/Documents.tex	Tue Jan 08 17:43:21 2002 +0100
+++ b/doc-src/TutorialI/Documents/document/Documents.tex	Tue Jan 08 17:51:56 2002 +0100
@@ -249,7 +249,9 @@
   \cite{isabelle-ref}.
 
   \medskip A typical example of syntax translations is to decorate
-  relational expressions with nice symbolic notation, such as \isa{{\isacharparenleft}x{\isacharcomma}\ y{\isacharparenright}\ {\isasymin}\ sim} versus \isa{x\ {\isasymapprox}\ y}.%
+  relational expressions (i.e.\ set-membership of tuples) with
+  handsome symbolic notation, such as \isa{{\isacharparenleft}x{\isacharcomma}\ y{\isacharparenright}\ {\isasymin}\ sim} versus
+  \isa{x\ {\isasymapprox}\ y}.%
 \end{isamarkuptext}%
 \isamarkuptrue%
 \isacommand{consts}\isanewline