--- a/lib/html/library_index_content.template Wed Nov 03 20:45:02 2021 +0100
+++ b/lib/html/library_index_content.template Wed Nov 03 20:53:52 2021 +0100
@@ -5,7 +5,7 @@
<ul>
<li><a href="HOL/index.html">HOL (Higher-Order Logic)</a>
is a version of classical higher-order logic resembling
- that of the <a href="http://www.cl.cam.ac.uk/Research/HVG/HOL/">HOL System</a>.
+ that of the <a href="https://www.cl.cam.ac.uk/Research/HVG/HOL/">HOL System</a>.
</li>
</ul>
</li>
--- a/src/Pure/Thy/presentation.scala Wed Nov 03 20:45:02 2021 +0100
+++ b/src/Pure/Thy/presentation.scala Wed Nov 03 20:53:52 2021 +0100
@@ -266,7 +266,7 @@
<center>
<table width="100%" border="0" cellspacing="10" cellpadding="0">
<tr>
- <td width="20%" valign="middle" align="center"><a href="http://isabelle.in.tum.de/"><img align="bottom" src="isabelle.gif" width="100" height="86" alt="[Isabelle]" border="0" /></a></td>
+ <td width="20%" valign="middle" align="center"><a href="https://isabelle.in.tum.de/"><img align="bottom" src="isabelle.gif" width="100" height="86" alt="[Isabelle]" border="0" /></a></td>
<td width="80%" valign="middle" align="center">
<table width="90%" border="0" cellspacing="0" cellpadding="20">