diff -r 83611262823e -r 0a7c6d78ad6b src/HOL/Nominal/Examples/SN.thy
--- a/src/HOL/Nominal/Examples/SN.thy	Sat May 20 23:36:55 2006 +0200
+++ b/src/HOL/Nominal/Examples/SN.thy	Sat May 20 23:36:56 2006 +0200
@@ -167,7 +167,7 @@
     TVar "string"
   | TArr "ty" "ty" (infix "\<rightarrow>" 200)
 
-primrec
+primrec (unchecked)
  "pi\<bullet>(TVar s) = TVar s"
  "pi\<bullet>(\<tau> \<rightarrow> \<sigma>) = (\<tau> \<rightarrow> \<sigma>)"