Typo.
diff --git a/Doc/lib/libdoctest.tex b/Doc/lib/libdoctest.tex
index 3fb4af1..63c0418 100644
--- a/Doc/lib/libdoctest.tex
+++ b/Doc/lib/libdoctest.tex
@@ -20,7 +20,7 @@
\item To perform regression testing by verifying that interactive
examples from a test file or a test object work as expected.
\item To write tutorial documentation for a package, liberally
- illustrated with input-ouput examples. Depending on whether
+ illustrated with input-output examples. Depending on whether
the examples or the expository text are emphasized, this has
the flavor of "literate testing" or "executable documentation".
\end{itemize}