theory LetRec2

imports "../Nominal2"

begin

atom_decl name

nominal_datatype trm =

  Var "name"

| App "trm" "trm"

| Lam x::"name" t::"trm"  binds x in t

| Let as::"assn" t::"trm"   binds "bn as" in t

| Let_rec as::"assn" t::"trm"   binds "bn as" in as t

and assn =

  ANil

| ACons "name" "trm" "assn"

binder

  bn

where

  "bn (ANil) = []"

| "bn (ACons x t as) = (atom x) # (bn as)"

thm trm_assn.eq_iff

thm trm_assn.supp

ML {*

@{term Trueprop} ;

@{const_name HOL.eq}

*}

thm trm_assn.fv_defs

thm trm_assn.eq_iff

thm trm_assn.bn_defs

thm trm_assn.perm_simps

thm trm_assn.induct

thm trm_assn.distinct

section {* Tests *}

(* why is this not in HOL simpset? *)

(*

lemma set_sub: "{a, b} - {b} = {a} - {b}"

by auto

lemma lets_bla:

  "x \<noteq> z \<Longrightarrow> y \<noteq> z \<Longrightarrow> x \<noteq> y \<Longrightarrow>(Lt (Lcons x (Vr y) Lnil) (Vr x)) \<noteq> (Lt (Lcons x (Vr z) Lnil) (Vr x))"

  apply (auto simp add: trm_lts.eq_iff alphas set_sub supp_at_base)

  done

lemma lets_ok:

  "(Lt (Lcons x (Vr x) Lnil) (Vr x)) = (Lt (Lcons y (Vr y) Lnil) (Vr y))"

  apply (simp add: trm_lts.eq_iff)

  apply (rule_tac x="(x \<leftrightarrow> y)" in exI)

  apply (simp_all add: alphas fresh_star_def eqvts supp_at_base)

  done

lemma lets_ok3:

  "x \<noteq> y \<Longrightarrow>

   (Lt (Lcons x (Ap (Vr y) (Vr x)) (Lcons y (Vr y) Lnil)) (Ap (Vr x) (Vr y))) \<noteq>

   (Lt (Lcons y (Ap (Vr x) (Vr y)) (Lcons x (Vr x) Lnil)) (Ap (Vr x) (Vr y)))"

  apply (simp add: alphas trm_lts.eq_iff)

  done

lemma lets_not_ok1:

  "x \<noteq> y \<Longrightarrow>

   (Lt (Lcons x (Vr x) (Lcons y (Vr y) Lnil)) (Ap (Vr x) (Vr y))) \<noteq>

   (Lt (Lcons y (Vr x) (Lcons x (Vr y) Lnil)) (Ap (Vr x) (Vr y)))"

  apply (simp add: alphas trm_lts.eq_iff)

  done

lemma lets_nok:

  "x \<noteq> y \<Longrightarrow> x \<noteq> z \<Longrightarrow> z \<noteq> y \<Longrightarrow>

   (Lt (Lcons x (Ap (Vr z) (Vr z)) (Lcons y (Vr z) Lnil)) (Ap (Vr x) (Vr y))) \<noteq>

   (Lt (Lcons y (Vr z) (Lcons x (Ap (Vr z) (Vr z)) Lnil)) (Ap (Vr x) (Vr y)))"

  apply (simp add: alphas trm_lts.eq_iff fresh_star_def)

  done

lemma lets_ok4:

  "(Lt (Lcons x (Ap (Vr y) (Vr x)) (Lcons y (Vr y) Lnil)) (Ap (Vr x) (Vr y))) =

   (Lt (Lcons y (Ap (Vr x) (Vr y)) (Lcons x (Vr x) Lnil)) (Ap (Vr y) (Vr x)))"

  apply (simp add: alphas trm_lts.eq_iff supp_at_base)

  apply (rule_tac x="(x \<leftrightarrow> y)" in exI)

  apply (simp add: atom_eqvt fresh_star_def)

  done

*)

end