--- a/Nominal/Ex/Height.thy	Sat Dec 17 17:10:11 2011 +0000
+++ b/Nominal/Ex/Height.thy	Sat Dec 17 17:31:40 2011 +0000
@@ -24,7 +24,7 @@
   have ih: "height (e1[x::=e']) \<le> height e1 - 1 + height e'" by fact
   moreover
   have vc: "atom y \<sharp> x" "atom y \<sharp> e'" by fact+ (* usual variable convention *)
-  ultimately show "height ((Lam y e1)[x::=e']) \<le> height (Lam y e1) - 1 + height e'" by simp
+  ultimately show "height ((Lam [y].e1)[x::=e']) \<le> height (Lam [y].e1) - 1 + height e'" by simp
 next    
   case (App e1 e2)
   have ih1: "height (e1[x::=e']) \<le> (height e1) - 1 + height e'"