--- a/src/Doc/Prog_Prove/document/intro-isabelle.tex Tue Feb 09 11:05:53 2016 +0100
+++ b/src/Doc/Prog_Prove/document/intro-isabelle.tex Tue Feb 09 16:38:43 2016 +0100
@@ -72,7 +72,7 @@
lower part of the window. You can examine the response to any input phrase
by clicking on that phrase or by hovering over underlined text.
-\begin{warn}
+\begin{warn}\label{proof-state}
By default Isabelle/jEdit does not show the proof state but this book
refers to it frequently. You should tick the ``Proof state'' box
to see the proof state in the output window.