--- a/src/Doc/Isar_Ref/Symbols.thy Sun Oct 03 21:29:34 2021 +0200
+++ b/src/Doc/Isar_Ref/Symbols.thy Mon Oct 04 13:32:34 2021 +0200
@@ -37,4 +37,6 @@
\end{center}
\<close>
+external_file %invisible \<open>~~/lib/texinputs/isabellesym.sty\<close>
+
end