--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Nominal/ExPS6.thy	Tue Mar 23 09:05:23 2010 +0100
@@ -0,0 +1,35 @@
+theory ExPS6
+imports "Parser"
+begin
+
+(* example 6 from Peter Sewell's bestiary *)
+
+atom_decl name
+
+ML {* val _ = recursive := false  *}
+nominal_datatype exp6 =
+  EVar name
+| EPair exp6 exp6
+| ELetRec x::name p::pat6 e1::exp6 e2::exp6 bind x in e1, bind x in e2, bind "bp6 p" in e1
+and pat6 =
+  PVar' name
+| PUnit'
+| PPair' pat6 pat6
+binder
+  bp6 :: "pat6 \<Rightarrow> atom set"
+where
+  "bp6 (PVar' x) = {atom x}"
+| "bp6 (PUnit') = {}"
+| "bp6 (PPair' p1 p2) = bp6 p1 \<union> bp6 p2"
+
+thm exp6_pat6.fv
+thm exp6_pat6.eq_iff
+thm exp6_pat6.bn
+thm exp6_pat6.perm
+thm exp6_pat6.induct
+thm exp6_pat6.distinct
+
+end
+
+
+