--- a/Nominal/Ex/Typing.thy Thu Jan 06 13:28:19 2011 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,149 +0,0 @@
-theory Lambda
-imports "../Nominal2"
-begin
-
-
-atom_decl name
-
-nominal_datatype lam =
- Var "name"
-| App "lam" "lam"
-| Lam x::"name" l::"lam" bind x in l
-
-thm lam.distinct
-thm lam.induct
-thm lam.exhaust lam.strong_exhaust
-thm lam.fv_defs
-thm lam.bn_defs
-thm lam.perm_simps
-thm lam.eq_iff
-thm lam.fv_bn_eqvt
-thm lam.size_eqvt
-
-
-section {* Typing *}
-
-nominal_datatype ty =
- TVar string
-| TFun ty ty ("_ \<rightarrow> _")
-
-lemma ty_fresh:
- fixes x::"name"
- and T::"ty"
- shows "atom x \<sharp> T"
-apply (nominal_induct T rule: ty.strong_induct)
-apply (simp_all add: ty.fresh pure_fresh)
-done
-
-inductive
- valid :: "(name \<times> ty) list \<Rightarrow> bool"
-where
- v_Nil[intro]: "valid []"
-| v_Cons[intro]: "\<lbrakk>atom x \<sharp> Gamma; valid Gamma\<rbrakk> \<Longrightarrow> valid ((x, T)#Gamma)"
-
-inductive
- typing :: "(name\<times>ty) list \<Rightarrow> lam \<Rightarrow> ty \<Rightarrow> bool" ("_ \<turnstile> _ : _" [60,60,60] 60)
-where
- t_Var[intro]: "\<lbrakk>valid \<Gamma>; (x, T) \<in> set \<Gamma>\<rbrakk> \<Longrightarrow> \<Gamma> \<turnstile> Var x : T"
- | t_App[intro]: "\<lbrakk>\<Gamma> \<turnstile> t1 : T1 \<rightarrow> T2; \<Gamma> \<turnstile> t2 : T1\<rbrakk> \<Longrightarrow> \<Gamma> \<turnstile> App t1 t2 : T2"
- | t_Lam[intro]: "\<lbrakk>atom x \<sharp> \<Gamma>; (x, T1) # \<Gamma> \<turnstile> t : T2\<rbrakk> \<Longrightarrow> \<Gamma> \<turnstile> Lam x t : T1 \<rightarrow> T2"
-
-thm typing.intros
-thm typing.induct
-
-equivariance valid
-equivariance typing
-
-nominal_inductive typing
- avoids t_Lam: "x"
- by (simp_all add: fresh_star_def ty_fresh lam.fresh)
-
-
-thm typing.strong_induct
-
-abbreviation
- "sub_context" :: "(name \<times> ty) list \<Rightarrow> (name \<times> ty) list \<Rightarrow> bool" ("_ \<subseteq> _" [60,60] 60)
-where
- "\<Gamma>1 \<subseteq> \<Gamma>2 \<equiv> \<forall>x T. (x, T) \<in> set \<Gamma>1 \<longrightarrow> (x, T) \<in> set \<Gamma>2"
-
-text {* Now it comes: The Weakening Lemma *}
-
-text {*
- The first version is, after setting up the induction,
- completely automatic except for use of atomize. *}
-
-lemma weakening_version2:
- fixes \<Gamma>1 \<Gamma>2::"(name \<times> ty) list"
- and t ::"lam"
- and \<tau> ::"ty"
- assumes a: "\<Gamma>1 \<turnstile> t : T"
- and b: "valid \<Gamma>2"
- and c: "\<Gamma>1 \<subseteq> \<Gamma>2"
- shows "\<Gamma>2 \<turnstile> t : T"
-using a b c
-proof (nominal_induct \<Gamma>1 t T avoiding: \<Gamma>2 rule: typing.strong_induct)
- case (t_Var \<Gamma>1 x T) (* variable case *)
- have "\<Gamma>1 \<subseteq> \<Gamma>2" by fact
- moreover
- have "valid \<Gamma>2" by fact
- moreover
- have "(x,T)\<in> set \<Gamma>1" by fact
- ultimately show "\<Gamma>2 \<turnstile> Var x : T" by auto
-next
- case (t_Lam x \<Gamma>1 T1 t T2) (* lambda case *)
- have vc: "atom x \<sharp> \<Gamma>2" by fact (* variable convention *)
- have ih: "\<lbrakk>valid ((x, T1) # \<Gamma>2); (x, T1) # \<Gamma>1 \<subseteq> (x, T1) # \<Gamma>2\<rbrakk> \<Longrightarrow> (x, T1) # \<Gamma>2 \<turnstile> t : T2" by fact
- have "\<Gamma>1 \<subseteq> \<Gamma>2" by fact
- then have "(x, T1) # \<Gamma>1 \<subseteq> (x, T1) # \<Gamma>2" by simp
- moreover
- have "valid \<Gamma>2" by fact
- then have "valid ((x, T1) # \<Gamma>2)" using vc by (simp add: v_Cons)
- ultimately have "(x, T1) # \<Gamma>2 \<turnstile> t : T2" using ih by simp
- with vc show "\<Gamma>2 \<turnstile> Lam x t : T1 \<rightarrow> T2" by auto
-qed (auto) (* app case *)
-
-lemma weakening_version1:
- fixes \<Gamma>1 \<Gamma>2::"(name \<times> ty) list"
- assumes a: "\<Gamma>1 \<turnstile> t : T"
- and b: "valid \<Gamma>2"
- and c: "\<Gamma>1 \<subseteq> \<Gamma>2"
- shows "\<Gamma>2 \<turnstile> t : T"
-using a b c
-apply (nominal_induct \<Gamma>1 t T avoiding: \<Gamma>2 rule: typing.strong_induct)
-apply (auto | atomize)+
-done
-
-
-inductive
- Acc :: "('a::pt \<Rightarrow> 'a \<Rightarrow> bool) \<Rightarrow> 'a \<Rightarrow> bool"
-where
- AccI: "(\<And>y. R y x \<Longrightarrow> Acc R y) \<Longrightarrow> Acc R x"
-
-
-lemma Acc_eqvt [eqvt]:
- fixes p::"perm"
- assumes a: "Acc R x"
- shows "Acc (p \<bullet> R) (p \<bullet> x)"
-using a
-apply(induct)
-apply(rule AccI)
-apply(rotate_tac 1)
-apply(drule_tac x="-p \<bullet> y" in meta_spec)
-apply(simp)
-apply(drule meta_mp)
-apply(rule_tac p="p" in permute_boolE)
-apply(perm_simp add: permute_minus_cancel)
-apply(assumption)
-apply(assumption)
-done
-
-
-nominal_inductive Acc .
-
-thm Acc.strong_induct
-
-
-end
-
-
-