--- a/doc-src/TutorialI/Types/types.tex Mon Mar 19 10:37:47 2001 +0100
+++ b/doc-src/TutorialI/Types/types.tex Mon Mar 19 12:38:36 2001 +0100
@@ -43,7 +43,7 @@
Isabelle offers the related concept of an \textbf{axiomatic type class}.
Roughly speaking, an axiomatic type class is a type class with axioms, i.e.\
an axiomatic specification of a class of types. Thus we can talk about a type
-$t$ being in a class $C$, which is written $\tau :: C$. This is the case if
+$\tau$ being in a class $C$, which is written $\tau :: C$. This is the case if
$\tau$ satisfies the axioms of $C$. Furthermore, type classes can be
organized in a hierarchy. Thus there is the notion of a class $D$ being a
\textbf{subclass} of a class $C$, written $D < C$. This is the case if all