--- a/src/Doc/Prog_Prove/document/intro-isabelle.tex Wed Jul 18 12:21:55 2018 +0200
+++ b/src/Doc/Prog_Prove/document/intro-isabelle.tex Wed Jul 18 16:44:01 2018 +0200
@@ -56,7 +56,7 @@
If you have not done so already, download and install Isabelle
(this book is compatible with Isabelle2016-1)
-from \url{http://isabelle.in.tum.de}. You can start it by clicking
+from \url{https://isabelle.in.tum.de}. You can start it by clicking
on the application icon. This will launch Isabelle's
user interface based on the text editor \concept{jEdit}. Below you see
a typical example snapshot of a session. At this point we merely explain