theory BlexerSimp2
imports Blexer2
begin
fun distinctWith :: "'a list \<Rightarrow> ('a \<Rightarrow> 'a \<Rightarrow> bool) \<Rightarrow> 'a set \<Rightarrow> 'a list"
where
"distinctWith [] eq acc = []"
| "distinctWith (x # xs) eq acc =
(if (\<exists> y \<in> acc. eq x y) then distinctWith xs eq acc
else x # (distinctWith xs eq ({x} \<union> acc)))"
fun eq1 ("_ ~1 _" [80, 80] 80) where
"AZERO ~1 AZERO = True"
| "(AONE bs1) ~1 (AONE bs2) = True"
| "(ACHAR bs1 c) ~1 (ACHAR bs2 d) = (if c = d then True else False)"
| "(ASEQs bs1 []) ~1 (ASEQs bs2 []) = True"
| "(ASEQs bs1 (r1#rs1)) ~1 (ASEQs bs2 (r2#rs2)) = (r1 ~1 r2 \<and> ASEQs [] rs1 ~1 ASEQs [] rs2)"
| "(AALTs bs1 []) ~1 (AALTs bs2 []) = True"
| "(AALTs bs1 (r1 # rs1)) ~1 (AALTs bs2 (r2 # rs2)) = (r1 ~1 r2 \<and> (AALTs bs1 rs1) ~1 (AALTs bs2 rs2))"
| "(ASTAR bs1 r1) ~1 (ASTAR bs2 r2) = r1 ~1 r2"
| "_ ~1 _ = False"
lemma eq1_L:
assumes "x ~1 y"
shows "L (erase x) = L (erase y)"
using assms
apply(induct rule: eq1.induct)
apply(auto elim: eq1.elims)
apply presburger
apply(case_tac rs1)
apply(simp)
apply (metis eq1.simps(28) erase.simps(8) neq_Nil_conv)
apply(simp)
apply (smt (verit, del_insts) L.simps(4) eq1.simps(22) erase.simps(9) erase_ASEQs list.exhaust)
apply(case_tac rs2)
apply(simp)
apply (metis eq1.simps(61) erase.simps(8) neq_Nil_conv)
apply(simp)
by (metis L.simps(4) eq1.simps(28) erase.simps(9) erase_ASEQs list.exhaust)
fun flts :: "arexp list \<Rightarrow> arexp list"
where
"flts [] = []"
| "flts (AZERO # rs) = flts rs"
| "flts ((AALTs bs rs1) # rs) = (map (fuse bs) rs1) @ flts rs"
| "flts (r1 # rs) = r1 # flts rs"
fun fuses1 :: "bit list \<Rightarrow> arexp list \<Rightarrow> arexp list"
where
"fuses1 _ [] = []"
| "fuses1 bs (r#rs) = (fuse bs r) # rs"
lemma fuses_length:
shows "length (fuses1 bs rs) < Suc (length rs)"
apply(induct bs rs rule:fuses1.induct)
apply(auto)
done
function (sequential) del :: "arexp list \<Rightarrow> arexp list \<Rightarrow> arexp list"
where
"del [] acc = acc"
| "del (AZERO#rs) acc = [AZERO]"
| "del ((AONE bs)#rs) acc = del (fuses1 bs rs) acc"
| "del ((ASEQs bs rs1)#rs2) acc = del rs2 (acc @ fuses1 bs rs1)"
| "del (r#rs) acc = del rs (acc @ [r])"
by pat_completeness auto
termination "del"
apply(relation "inv_image (measure(%cs. size cs) <*lex*> measure(%s. size s)) (%(ds,r). (ds, r))")
apply(auto simp add: fuses_length)
done
fun bsimp_ASEQs :: "bit list \<Rightarrow> arexp list \<Rightarrow> arexp"
where
"bsimp_ASEQs _ [AZERO] = AZERO"
| "bsimp_ASEQs bs [] = AONE bs"
| "bsimp_ASEQs bs [r] = fuse bs r"
| "bsimp_ASEQs bs rs = ASEQs bs rs"
fun bsimp_AALTs :: "bit list \<Rightarrow> arexp list \<Rightarrow> arexp"
where
"bsimp_AALTs _ [] = AZERO"
| "bsimp_AALTs bs1 [r] = fuse bs1 r"
| "bsimp_AALTs bs1 rs = AALTs bs1 rs"
fun bsimp :: "arexp \<Rightarrow> arexp"
where
"bsimp (ASEQs bs1 rs) = bsimp_ASEQs bs1 (del (map bsimp rs) [])"
| "bsimp (AALTs bs1 rs) = bsimp_AALTs bs1 (distinctWith (flts (map bsimp rs)) eq1 {}) "
| "bsimp r = r"
fun
bders_simp :: "arexp \<Rightarrow> string \<Rightarrow> arexp"
where
"bders_simp r [] = r"
| "bders_simp r (c # s) = bders_simp (bsimp (bder c r)) s"
definition blexer_simp where
"blexer_simp r s \<equiv> if bnullable (bders_simp (intern r) s) then
decode (bmkeps (bders_simp (intern r) s)) r else None"
lemma bders_simp_append:
shows "bders_simp r (s1 @ s2) = bders_simp (bders_simp r s1) s2"
apply(induct s1 arbitrary: r s2)
apply(simp_all)
done
lemma bmkeps_fuse:
assumes "bnullable r"
shows "bmkeps (fuse bs r) = bs @ bmkeps r"
using assms
by (induct r rule: bnullable.induct) (auto)
lemma bmkepss_fuse:
assumes "bnullables rs"
shows "bmkepss (map (fuse bs) rs) = bs @ bmkepss rs"
using assms
apply(induct rs arbitrary: bs)
apply(auto simp add: bmkeps_fuse bnullable_fuse)
done
lemma bder_fuse:
shows "bder c (fuse bs a) = fuse bs (bder c a)"
apply(induct c a arbitrary: bs rule: bder.induct)
apply(simp_all)[6]
using fuse_append apply presburger
apply (metis bder.simps(7) fuse.simps(4) fuse.simps(5))
by simp
inductive
rrewrite:: "arexp \<Rightarrow> arexp \<Rightarrow> bool" ("_ \<leadsto> _" [99, 99] 99)
and
srewrite:: "arexp list \<Rightarrow> arexp list \<Rightarrow> bool" (" _ s\<leadsto> _" [100, 100] 100)
where
bs1: "(\<exists>r \<in> set rs. r = AZERO) \<Longrightarrow> ASEQs bs rs \<leadsto> AZERO"
| bs3: "ASEQs bs1 (rs1 @ [AONE bs2] @ rs2) \<leadsto> ASEQs bs1 (rs1 @ fuses1 bs2 rs2)"
| bs4: "rs1 s\<leadsto> rs2 \<Longrightarrow> ASEQs bs rs1 \<leadsto> ASEQs bs rs2"
| bs5: "r3 \<leadsto> r4 \<Longrightarrow> ASEQ bs r1 r3 \<leadsto> ASEQ bs r1 r4"
| bs6: "AALTs bs [] \<leadsto> AZERO"
| bs7: "AALTs bs [r] \<leadsto> fuse bs r"
| bs10: "rs1 s\<leadsto> rs2 \<Longrightarrow> AALTs bs rs1 \<leadsto> AALTs bs rs2"
| ss1: "[] s\<leadsto> []"
| ss2: "rs1 s\<leadsto> rs2 \<Longrightarrow> (r # rs1) s\<leadsto> (r # rs2)"
| ss3: "r1 \<leadsto> r2 \<Longrightarrow> (r1 # rs) s\<leadsto> (r2 # rs)"
| ss4: "(AZERO # rs) s\<leadsto> rs"
| ss5: "(AALTs bs1 rs1 # rsb) s\<leadsto> ((map (fuse bs1) rs1) @ rsb)"
| ss6: "L (erase a2) \<subseteq> L (erase a1) \<Longrightarrow> (rsa@[a1]@rsb@[a2]@rsc) s\<leadsto> (rsa@[a1]@rsb@rsc)"
inductive
rrewrites:: "arexp \<Rightarrow> arexp \<Rightarrow> bool" ("_ \<leadsto>* _" [100, 100] 100)
where
rs1[intro, simp]:"r \<leadsto>* r"
| rs2[intro]: "\<lbrakk>r1 \<leadsto>* r2; r2 \<leadsto> r3\<rbrakk> \<Longrightarrow> r1 \<leadsto>* r3"
inductive
srewrites:: "arexp list \<Rightarrow> arexp list \<Rightarrow> bool" ("_ s\<leadsto>* _" [100, 100] 100)
where
sss1[intro, simp]:"rs s\<leadsto>* rs"
| sss2[intro]: "\<lbrakk>rs1 s\<leadsto> rs2; rs2 s\<leadsto>* rs3\<rbrakk> \<Longrightarrow> rs1 s\<leadsto>* rs3"
lemma r_in_rstar : "r1 \<leadsto> r2 \<Longrightarrow> r1 \<leadsto>* r2"
using rrewrites.intros(1) rrewrites.intros(2) by blast
lemma rs_in_rstar:
shows "r1 s\<leadsto> r2 \<Longrightarrow> r1 s\<leadsto>* r2"
using rrewrites.intros(1) rrewrites.intros(2) by blast
lemma rrewrites_trans[trans]:
assumes a1: "r1 \<leadsto>* r2" and a2: "r2 \<leadsto>* r3"
shows "r1 \<leadsto>* r3"
using a2 a1
apply(induct r2 r3 arbitrary: r1 rule: rrewrites.induct)
apply(auto)
done
lemma srewrites_trans[trans]:
assumes a1: "r1 s\<leadsto>* r2" and a2: "r2 s\<leadsto>* r3"
shows "r1 s\<leadsto>* r3"
using a1 a2
apply(induct r1 r2 arbitrary: r3 rule: srewrites.induct)
apply(auto)
done
lemma contextrewrites0:
"rs1 s\<leadsto>* rs2 \<Longrightarrow> AALTs bs rs1 \<leadsto>* AALTs bs rs2"
apply(induct rs1 rs2 rule: srewrites.inducts)
apply simp
using bs10 r_in_rstar rrewrites_trans by blast
lemma contextrewrites1:
"r \<leadsto>* r' \<Longrightarrow> AALTs bs (r # rs) \<leadsto>* AALTs bs (r' # rs)"
apply(induct r r' rule: rrewrites.induct)
apply simp
using bs10 ss3 by blast
lemma srewrite1:
shows "rs1 s\<leadsto> rs2 \<Longrightarrow> (rs @ rs1) s\<leadsto> (rs @ rs2)"
apply(induct rs)
apply(auto)
using ss2 by auto
lemma srewrites1:
shows "rs1 s\<leadsto>* rs2 \<Longrightarrow> (rs @ rs1) s\<leadsto>* (rs @ rs2)"
apply(induct rs1 rs2 rule: srewrites.induct)
apply(auto)
using srewrite1 by blast
lemma srewrite2:
shows "r1 \<leadsto> r2 \<Longrightarrow> True"
and "rs1 s\<leadsto> rs2 \<Longrightarrow> (rs1 @ rs) s\<leadsto>* (rs2 @ rs)"
apply(induct rule: rrewrite_srewrite.inducts)
apply(auto)
apply (metis append_Cons append_Nil srewrites1)
apply(meson srewrites.simps ss3)
apply (meson srewrites.simps ss4)
apply (meson srewrites.simps ss5)
by (metis append_Cons append_Nil srewrites.simps ss6)
lemma srewrites3:
shows "rs1 s\<leadsto>* rs2 \<Longrightarrow> (rs1 @ rs) s\<leadsto>* (rs2 @ rs)"
apply(induct rs1 rs2 arbitrary: rs rule: srewrites.induct)
apply(auto)
by (meson srewrite2(2) srewrites_trans)
(*
lemma srewrites4:
assumes "rs3 s\<leadsto>* rs4" "rs1 s\<leadsto>* rs2"
shows "(rs1 @ rs3) s\<leadsto>* (rs2 @ rs4)"
using assms
apply(induct rs3 rs4 arbitrary: rs1 rs2 rule: srewrites.induct)
apply (simp add: srewrites3)
using srewrite1 by blast
*)
lemma srewrites6:
assumes "r1 \<leadsto>* r2"
shows "[r1] s\<leadsto>* [r2]"
using assms
apply(induct r1 r2 rule: rrewrites.induct)
apply(auto)
by (meson srewrites.simps srewrites_trans ss3)
lemma srewrites7:
assumes "rs3 s\<leadsto>* rs4" "r1 \<leadsto>* r2"
shows "(r1 # rs3) s\<leadsto>* (r2 # rs4)"
using assms
by (smt (verit, best) append_Cons append_Nil srewrites1 srewrites3 srewrites6 srewrites_trans)
lemma ss6_stronger_aux:
shows "(rs1 @ rs2) s\<leadsto>* (rs1 @ distinctWith rs2 eq1 (set rs1))"
apply(induct rs2 arbitrary: rs1)
apply(auto)
prefer 2
apply(drule_tac x="rs1 @ [a]" in meta_spec)
apply(simp)
apply(drule_tac x="rs1" in meta_spec)
apply(subgoal_tac "(rs1 @ a # rs2) s\<leadsto>* (rs1 @ rs2)")
using srewrites_trans apply blast
apply(subgoal_tac "\<exists>rs1a rs1b. rs1 = rs1a @ [x] @ rs1b")
prefer 2
apply (simp add: split_list)
apply(erule exE)+
apply(simp)
using eq1_L rs_in_rstar ss6 by force
lemma ss6_stronger:
shows "rs1 s\<leadsto>* distinctWith rs1 eq1 {}"
by (metis append_Nil list.set(1) ss6_stronger_aux)
lemma rewrite_preserves_fuse:
shows "r2 \<leadsto> r3 \<Longrightarrow> fuse bs r2 \<leadsto> fuse bs r3"
and "rs2 s\<leadsto> rs3 \<Longrightarrow> map (fuse bs) rs2 s\<leadsto>* map (fuse bs) rs3"
proof(induct rule: rrewrite_srewrite.inducts)
case (bs3 bs1 bs2 r)
then show ?case
by (metis fuse.simps(5) fuse_append rrewrite_srewrite.bs3)
next
case (bs7 bs r)
then show ?case
by (metis fuse.simps(4) fuse_append rrewrite_srewrite.bs7)
next
case (ss2 rs1 rs2 r)
then show ?case
using srewrites7 by force
next
case (ss3 r1 r2 rs)
then show ?case by (simp add: r_in_rstar srewrites7)
next
case (ss5 bs1 rs1 rsb)
then show ?case
apply(simp)
by (metis (mono_tags, lifting) comp_def fuse_append map_eq_conv rrewrite_srewrite.ss5 srewrites.simps)
next
case (ss6 a1 a2 rsa rsb rsc)
then show ?case
apply(simp only: map_append)
by (smt (verit, best) erase_fuse list.simps(8) list.simps(9) rrewrite_srewrite.ss6 srewrites.simps)
qed (auto intro: rrewrite_srewrite.intros)
lemma rewrites_fuse:
assumes "r1 \<leadsto>* r2"
shows "fuse bs r1 \<leadsto>* fuse bs r2"
using assms
apply(induction r1 r2 arbitrary: bs rule: rrewrites.induct)
apply(auto intro: rewrite_preserves_fuse rrewrites_trans)
done
lemma star_seqs:
assumes "rs1 s\<leadsto>* rs2"
shows "ASEQs bs rs1 \<leadsto>* ASEQs bs rs2"
using assms
apply(induct rs1 rs2 arbitrary: rule: rrewrites.induct)
apply(auto intro: rrewrite_srewrite.intros)
done
lemma star_seq:
assumes "r1 \<leadsto>* r2"
shows "ASEQ bs r1 r3 \<leadsto>* ASEQ bs r2 r3"
using assms
apply(induct r1 r2 arbitrary: r3 rule: rrewrites.induct)
apply(auto intro: rrewrite_srewrite.intros)
done
lemma star_seq2:
assumes "r3 \<leadsto>* r4"
shows "ASEQ bs r1 r3 \<leadsto>* ASEQ bs r1 r4"
using assms
apply(induct r3 r4 arbitrary: r1 rule: rrewrites.induct)
apply(auto intro: rrewrite_srewrite.intros)
done
lemma continuous_rewrite:
assumes "r1 \<leadsto>* AZERO"
shows "ASEQ bs1 r1 r2 \<leadsto>* AZERO"
using assms bs1 star_seq by blast
(*
lemma continuous_rewrite2:
assumes "r1 \<leadsto>* AONE bs"
shows "ASEQ bs1 r1 r2 \<leadsto>* (fuse (bs1 @ bs) r2)"
using assms by (meson bs3 rrewrites.simps star_seq)
*)
lemma bsimp_aalts_simpcases:
shows "AONE bs \<leadsto>* bsimp (AONE bs)"
and "AZERO \<leadsto>* bsimp AZERO"
and "ACHAR bs c \<leadsto>* bsimp (ACHAR bs c)"
by (simp_all)
lemma bsimp_ASEQs_rewrites:
shows "ASEQs bs1 rs \<leadsto>* bsimp_ASEQs bs1 rs"
lemma bsimp_AALTs_rewrites:
shows "AALTs bs1 rs \<leadsto>* bsimp_AALTs bs1 rs"
by (smt (verit) bs6 bs7 bsimp_AALTs.elims rrewrites.simps)
lemma trivialbsimp_srewrites:
"\<lbrakk>\<And>x. x \<in> set rs \<Longrightarrow> x \<leadsto>* f x \<rbrakk> \<Longrightarrow> rs s\<leadsto>* (map f rs)"
apply(induction rs)
apply simp
apply(simp)
using srewrites7 by auto
lemma fltsfrewrites: "rs s\<leadsto>* flts rs"
apply(induction rs rule: flts.induct)
apply(auto intro: rrewrite_srewrite.intros)
apply (meson srewrites.simps srewrites1 ss5)
using rs1 srewrites7 apply presburger
using srewrites7 apply force
apply (simp add: srewrites7)
by (simp add: srewrites7)
lemma bnullable0:
shows "r1 \<leadsto> r2 \<Longrightarrow> bnullable r1 = bnullable r2"
and "rs1 s\<leadsto> rs2 \<Longrightarrow> bnullables rs1 = bnullables rs2"
apply(induct rule: rrewrite_srewrite.inducts)
apply(auto simp add: bnullable_fuse)
apply (meson UnCI bnullable_fuse imageI)
using bnullable_correctness nullable_correctness by blast
lemma rewritesnullable:
assumes "r1 \<leadsto>* r2"
shows "bnullable r1 = bnullable r2"
using assms
apply(induction r1 r2 rule: rrewrites.induct)
apply simp
using bnullable0(1) by auto
lemma rewrite_bmkeps_aux:
shows "r1 \<leadsto> r2 \<Longrightarrow> (bnullable r1 \<and> bnullable r2 \<Longrightarrow> bmkeps r1 = bmkeps r2)"
and "rs1 s\<leadsto> rs2 \<Longrightarrow> (bnullables rs1 \<and> bnullables rs2 \<Longrightarrow> bmkepss rs1 = bmkepss rs2)"
proof (induct rule: rrewrite_srewrite.inducts)
case (bs3 bs1 bs2 r)
then show ?case by (simp add: bmkeps_fuse)
next
case (bs7 bs r)
then show ?case by (simp add: bmkeps_fuse)
next
case (ss3 r1 r2 rs)
then show ?case
using bmkepss.simps bnullable0(1) by presburger
next
case (ss5 bs1 rs1 rsb)
then show ?case
by (simp add: bmkepss1 bmkepss2 bmkepss_fuse bnullable_fuse)
next
case (ss6 a1 a2 rsa rsb rsc)
then show ?case
by (smt (verit, best) Nil_is_append_conv bmkepss1 bmkepss2 bnullable_correctness in_set_conv_decomp list.distinct(1) list.set_intros(1) nullable_correctness set_ConsD subsetD)
qed (auto)
lemma rewrites_bmkeps:
assumes "r1 \<leadsto>* r2" "bnullable r1"
shows "bmkeps r1 = bmkeps r2"
using assms
proof(induction r1 r2 rule: rrewrites.induct)
case (rs1 r)
then show "bmkeps r = bmkeps r" by simp
next
case (rs2 r1 r2 r3)
then have IH: "bmkeps r1 = bmkeps r2" by simp
have a1: "bnullable r1" by fact
have a2: "r1 \<leadsto>* r2" by fact
have a3: "r2 \<leadsto> r3" by fact
have a4: "bnullable r2" using a1 a2 by (simp add: rewritesnullable)
then have "bmkeps r2 = bmkeps r3"
using a3 bnullable0(1) rewrite_bmkeps_aux(1) by blast
then show "bmkeps r1 = bmkeps r3" using IH by simp
qed
lemma rewrites_to_bsimp:
shows "r \<leadsto>* bsimp r"
proof (induction r rule: bsimp.induct)
case (1 bs1 rs)
(*
have IH1: "r1 \<leadsto>* bsimp r1" by fact
have IH2: "r2 \<leadsto>* bsimp r2" by fact
{ assume as: "bsimp r1 = AZERO \<or> bsimp r2 = AZERO"
with IH1 IH2 have "r1 \<leadsto>* AZERO \<or> r2 \<leadsto>* AZERO" by auto
then have "ASEQ bs1 r1 r2 \<leadsto>* AZERO"
by (metis bs2 continuous_rewrite rrewrites.simps star_seq2)
then have "ASEQ bs1 r1 r2 \<leadsto>* bsimp (ASEQ bs1 r1 r2)" using as by auto
}
moreover
{ assume "\<exists>bs. bsimp r1 = AONE bs"
then obtain bs where as: "bsimp r1 = AONE bs" by blast
with IH1 have "r1 \<leadsto>* AONE bs" by simp
then have "ASEQ bs1 r1 r2 \<leadsto>* fuse (bs1 @ bs) r2" using bs3 star_seq by blast
with IH2 have "ASEQ bs1 r1 r2 \<leadsto>* fuse (bs1 @ bs) (bsimp r2)"
using rewrites_fuse by (meson rrewrites_trans)
then have "ASEQ bs1 r1 r2 \<leadsto>* bsimp (ASEQ bs1 (AONE bs) r2)" by simp
then have "ASEQ bs1 r1 r2 \<leadsto>* bsimp (ASEQ bs1 r1 r2)" by (simp add: as)
}
moreover
{ assume as1: "bsimp r1 \<noteq> AZERO" "bsimp r2 \<noteq> AZERO" and as2: "(\<nexists>bs. bsimp r1 = AONE bs)"
then have "bsimp_ASEQ bs1 (bsimp r1) (bsimp r2) = ASEQ bs1 (bsimp r1) (bsimp r2)"
by (simp add: bsimp_ASEQ1)
then have "ASEQ bs1 r1 r2 \<leadsto>* bsimp_ASEQ bs1 (bsimp r1) (bsimp r2)" using as1 as2 IH1 IH2
by (metis rrewrites_trans star_seq star_seq2)
then have "ASEQ bs1 r1 r2 \<leadsto>* bsimp (ASEQ bs1 r1 r2)" by simp
}
ultimately show "ASEQ bs1 r1 r2 \<leadsto>* bsimp (ASEQ bs1 r1 r2)" by blast
*)
show ?case
apply(simp)
sorry
next
case (2 bs1 rs)
have IH: "\<And>x. x \<in> set rs \<Longrightarrow> x \<leadsto>* bsimp x" by fact
then have "rs s\<leadsto>* (map bsimp rs)" by (simp add: trivialbsimp_srewrites)
also have "... s\<leadsto>* flts (map bsimp rs)" by (simp add: fltsfrewrites)
also have "... s\<leadsto>* distinctWith (flts (map bsimp rs)) eq1 {}" by (simp add: ss6_stronger)
finally have "AALTs bs1 rs \<leadsto>* AALTs bs1 (distinctWith (flts (map bsimp rs)) eq1 {})"
using contextrewrites0 by auto
also have "... \<leadsto>* bsimp_AALTs bs1 (distinctWith (flts (map bsimp rs)) eq1 {})"
by (simp add: bsimp_AALTs_rewrites)
finally show "AALTs bs1 rs \<leadsto>* bsimp (AALTs bs1 rs)" by simp
qed (simp_all)
lemma to_zero_in_alt:
shows "AALT bs (ASEQ [] AZERO r) r2 \<leadsto> AALT bs AZERO r2"
by (simp add: bs1 bs10 ss3)
lemma bder_fuse_list:
shows "map (bder c \<circ> fuse bs1) rs1 = map (fuse bs1 \<circ> bder c) rs1"
apply(induction rs1)
apply(simp_all add: bder_fuse)
done
lemma map1:
shows "(map f [a]) = [f a]"
by (simp)
lemma rewrite_preserves_bder:
shows "r1 \<leadsto> r2 \<Longrightarrow> (bder c r1) \<leadsto>* (bder c r2)"
and "rs1 s\<leadsto> rs2 \<Longrightarrow> map (bder c) rs1 s\<leadsto>* map (bder c) rs2"
proof(induction rule: rrewrite_srewrite.inducts)
case (bs1 bs r2)
then show ?case
by (simp add: continuous_rewrite)
next
case (bs2 bs r1)
then show ?case
apply(auto)
apply (meson bs6 contextrewrites0 rrewrite_srewrite.bs2 rs2 ss3 ss4 sss1 sss2)
by (simp add: r_in_rstar rrewrite_srewrite.bs2)
next
case (bs3 bs1 bs2 r)
then show ?case
apply(simp)
sorry
next
case (bs4 r1 r2 bs r3)
have as: "r1 \<leadsto> r2" by fact
have IH: "bder c r1 \<leadsto>* bder c r2" by fact
from as IH show "bder c (ASEQ bs r1 r3) \<leadsto>* bder c (ASEQ bs r2 r3)"
sorry
next
case (bs5 r3 r4 bs r1)
have as: "r3 \<leadsto> r4" by fact
have IH: "bder c r3 \<leadsto>* bder c r4" by fact
from as IH show "bder c (ASEQ bs r1 r3) \<leadsto>* bder c (ASEQ bs r1 r4)"
apply(simp)
apply(auto)
using contextrewrites0 r_in_rstar rewrites_fuse srewrites6 srewrites7 star_seq2 apply presburger
using star_seq2 by blast
next
case (bs6 bs)
then show ?case
using rrewrite_srewrite.bs6 by force
next
case (bs7 bs r)
then show ?case
by (simp add: bder_fuse r_in_rstar rrewrite_srewrite.bs7)
next
case (bs10 rs1 rs2 bs)
then show ?case
using contextrewrites0 by force
next
case ss1
then show ?case by simp
next
case (ss2 rs1 rs2 r)
then show ?case
by (simp add: srewrites7)
next
case (ss3 r1 r2 rs)
then show ?case
by (simp add: srewrites7)
next
case (ss4 rs)
then show ?case
using rrewrite_srewrite.ss4 by fastforce
next
case (ss5 bs1 rs1 rsb)
then show ?case
apply(simp)
using bder_fuse_list map_map rrewrite_srewrite.ss5 srewrites.simps by blast
next
case (ss6 a1 a2 bs rsa rsb)
then show ?case
apply(simp only: map_append map1)
apply(rule srewrites_trans)
apply(rule rs_in_rstar)
apply(rule_tac rrewrite_srewrite.ss6)
using Der_def der_correctness apply auto[1]
by blast
qed
lemma rewrites_preserves_bder:
assumes "r1 \<leadsto>* r2"
shows "bder c r1 \<leadsto>* bder c r2"
using assms
apply(induction r1 r2 rule: rrewrites.induct)
apply(simp_all add: rewrite_preserves_bder rrewrites_trans)
done
lemma central:
shows "bders r s \<leadsto>* bders_simp r s"
proof(induct s arbitrary: r rule: rev_induct)
case Nil
then show "bders r [] \<leadsto>* bders_simp r []" by simp
next
case (snoc x xs)
have IH: "\<And>r. bders r xs \<leadsto>* bders_simp r xs" by fact
have "bders r (xs @ [x]) = bders (bders r xs) [x]" by (simp add: bders_append)
also have "... \<leadsto>* bders (bders_simp r xs) [x]" using IH
by (simp add: rewrites_preserves_bder)
also have "... \<leadsto>* bders_simp (bders_simp r xs) [x]" using IH
by (simp add: rewrites_to_bsimp)
finally show "bders r (xs @ [x]) \<leadsto>* bders_simp r (xs @ [x])"
by (simp add: bders_simp_append)
qed
lemma main_aux:
assumes "bnullable (bders r s)"
shows "bmkeps (bders r s) = bmkeps (bders_simp r s)"
proof -
have "bders r s \<leadsto>* bders_simp r s" by (rule central)
then
show "bmkeps (bders r s) = bmkeps (bders_simp r s)" using assms
by (rule rewrites_bmkeps)
qed
theorem main_blexer_simp:
shows "blexer r s = blexer_simp r s"
unfolding blexer_def blexer_simp_def
by (metis central main_aux rewritesnullable)
theorem blexersimp_correctness:
shows "lexer r s = blexer_simp r s"
using blexer_correctness main_blexer_simp by simp
unused_thms
end