diff -r 0afff550c157 -r 48f1fb0b8895 Nominal/main.html
--- a/Nominal/main.html	Wed Mar 30 16:56:26 2016 +0100
+++ b/Nominal/main.html	Wed Mar 30 17:01:15 2016 +0100
@@ -72,7 +72,7 @@
 <A HREF="example.html">here</A>. For more interesting results, we already
 completed formalisations of Church-Rosser and strong-normalisation proofs as
 well as the first part of the <A
-HREF="http://www.cis.upenn.edu/group/proj/plclub/mmm/" target="_top">PoplMark
+HREF="https://www.seas.upenn.edu/~plclub/poplmark/" target="_top">PoplMark
 Challenge</A>.  We also formalised some typical proofs from SOS, <A
 HREF="http://www.cs.cmu.edu/~crary/" target="_top">Karl Crary</A>'s chapter on
 logical relations from <A