--- a/src/HOL/Induct/document/root.tex Wed Dec 30 20:12:26 2015 +0100
+++ b/src/HOL/Induct/document/root.tex Wed Dec 30 20:24:43 2015 +0100
@@ -1,5 +1,5 @@
-
\documentclass[11pt,a4paper]{article}
+\usepackage{amssymb}
\usepackage{isabelle,isabellesym,pdfsetup}
%for best-style documents ...