thys/Simplifying.thy
changeset 150 09f81fee11ce
child 151 5a1196466a9c
equal deleted inserted replaced
149:ec3d221bfc45 150:09f81fee11ce
       
     1 theory Simplifying
       
     2   imports "ReStar" 
       
     3 begin
       
     4 
       
     5 section {* Lexer including simplifications *}
       
     6 
       
     7 
       
     8 fun F_RIGHT where
       
     9   "F_RIGHT f v = Right (f v)"
       
    10 
       
    11 fun F_LEFT where
       
    12   "F_LEFT f v = Left (f v)"
       
    13 
       
    14 fun F_ALT where
       
    15   "F_ALT f\<^sub>1 f\<^sub>2 (Right v) = Right (f\<^sub>2 v)"
       
    16 | "F_ALT f\<^sub>1 f\<^sub>2 (Left v) = Left (f\<^sub>1 v)"  
       
    17 | "F_ALT f1 f2 v = v"
       
    18 
       
    19 
       
    20 fun F_SEQ1 where
       
    21   "F_SEQ1 f\<^sub>1 f\<^sub>2 v = Seq (f\<^sub>1 Void) (f\<^sub>2 v)"
       
    22 
       
    23 fun F_SEQ2 where 
       
    24   "F_SEQ2 f\<^sub>1 f\<^sub>2 v = Seq (f\<^sub>1 v) (f\<^sub>2 Void)"
       
    25 
       
    26 fun F_SEQ where 
       
    27   "F_SEQ f\<^sub>1 f\<^sub>2 (Seq v\<^sub>1 v\<^sub>2) = Seq (f\<^sub>1 v\<^sub>1) (f\<^sub>2 v\<^sub>2)"
       
    28 | "F_SEQ f1 f2 v = v"
       
    29 
       
    30 fun simp_ALT where
       
    31   "simp_ALT (ZERO, f\<^sub>1) (r\<^sub>2, f\<^sub>2) = (r\<^sub>2, F_RIGHT f\<^sub>2)"
       
    32 | "simp_ALT (r\<^sub>1, f\<^sub>1) (ZERO, f\<^sub>2) = (r\<^sub>1, F_LEFT f\<^sub>1)"
       
    33 | "simp_ALT (r\<^sub>1, f\<^sub>1) (r\<^sub>2, f\<^sub>2) = (ALT r\<^sub>1 r\<^sub>2, F_ALT f\<^sub>1 f\<^sub>2)"
       
    34 
       
    35 fun simp_SEQ where
       
    36   "simp_SEQ (ONE, f\<^sub>1) (r\<^sub>2, f\<^sub>2) = (r\<^sub>2, F_SEQ1 f\<^sub>1 f\<^sub>2)"
       
    37 | "simp_SEQ (r\<^sub>1, f\<^sub>1) (ONE, f\<^sub>2) = (r\<^sub>1, F_SEQ2 f\<^sub>1 f\<^sub>2)"
       
    38 | "simp_SEQ (r\<^sub>1, f\<^sub>1) (r\<^sub>2, f\<^sub>2) = (SEQ r\<^sub>1 r\<^sub>2, F_SEQ f\<^sub>1 f\<^sub>2)"  
       
    39  
       
    40 lemma simp_SEQ_simps:
       
    41   "simp_SEQ p1 p2 = (if (fst p1 = ONE) then (fst p2, F_SEQ1 (snd p1) (snd p2))
       
    42                     else (if (fst p2 = ONE) then (fst p1, F_SEQ2 (snd p1) (snd p2))
       
    43                     else (SEQ (fst p1) (fst p2), F_SEQ (snd p1) (snd p2))))"
       
    44 apply(auto)
       
    45 apply(case_tac p1)
       
    46 apply(case_tac p2)
       
    47 apply(simp)
       
    48 apply(case_tac p1)
       
    49 apply(case_tac p2)
       
    50 apply(simp)
       
    51 apply(case_tac a)
       
    52 apply(simp_all)
       
    53 apply(case_tac p1)
       
    54 apply(case_tac p2)
       
    55 apply(simp)
       
    56 apply(case_tac p1)
       
    57 apply(case_tac p2)
       
    58 apply(simp)
       
    59 apply(case_tac a)
       
    60 apply(simp_all)
       
    61 apply(case_tac aa)
       
    62 apply(simp_all)
       
    63 apply(auto)
       
    64 apply(case_tac aa)
       
    65 apply(simp_all)
       
    66 apply(case_tac aa)
       
    67 apply(simp_all)
       
    68 apply(case_tac aa)
       
    69 apply(simp_all)
       
    70 apply(case_tac aa)
       
    71 apply(simp_all)
       
    72 done
       
    73 
       
    74 lemma simp_ALT_simps:
       
    75   "simp_ALT p1 p2 = (if (fst p1 = ZERO) then (fst p2, F_RIGHT (snd p2))
       
    76                     else (if (fst p2 = ZERO) then (fst p1, F_LEFT (snd p1))
       
    77                     else (ALT (fst p1) (fst p2), F_ALT (snd p1) (snd p2))))"
       
    78 apply(auto)
       
    79 apply(case_tac p1)
       
    80 apply(case_tac p2)
       
    81 apply(simp)
       
    82 apply(case_tac p1)
       
    83 apply(case_tac p2)
       
    84 apply(simp)
       
    85 apply(case_tac a)
       
    86 apply(simp_all)
       
    87 apply(case_tac p1)
       
    88 apply(case_tac p2)
       
    89 apply(simp)
       
    90 apply(case_tac p1)
       
    91 apply(case_tac p2)
       
    92 apply(simp)
       
    93 apply(case_tac a)
       
    94 apply(simp_all)
       
    95 apply(case_tac aa)
       
    96 apply(simp_all)
       
    97 apply(auto)
       
    98 apply(case_tac aa)
       
    99 apply(simp_all)
       
   100 apply(case_tac aa)
       
   101 apply(simp_all)
       
   102 apply(case_tac aa)
       
   103 apply(simp_all)
       
   104 apply(case_tac aa)
       
   105 apply(simp_all)
       
   106 done
       
   107 
       
   108 
       
   109 fun 
       
   110   simp :: "rexp \<Rightarrow> rexp * (val \<Rightarrow> val)"
       
   111 where
       
   112   "simp (ALT r1 r2) = simp_ALT (simp r1) (simp r2)" 
       
   113 | "simp (SEQ r1 r2) = simp_SEQ (simp r1) (simp r2)" 
       
   114 | "simp r = (r, id)"
       
   115 
       
   116 fun 
       
   117   slexer :: "rexp \<Rightarrow> string \<Rightarrow> val option"
       
   118 where
       
   119   "slexer r [] = (if nullable r then Some(mkeps r) else None)"
       
   120 | "slexer r (c#s) = (let (rs, fr) = simp (der c r) in
       
   121                          (case (slexer rs s) of  
       
   122                             None \<Rightarrow> None
       
   123                           | Some(v) \<Rightarrow> Some(injval r c (fr v))))"
       
   124 
       
   125 
       
   126 lemma L_fst_simp:
       
   127   shows "L(r) = L(fst (simp r))"
       
   128 using assms
       
   129 apply(induct r rule: rexp.induct)
       
   130 apply(auto simp add: simp_SEQ_simps simp_ALT_simps)
       
   131 done
       
   132 
       
   133 lemma 
       
   134   shows "\<turnstile> ((snd (simp r)) v) : r \<longleftrightarrow> \<turnstile> v : (fst (simp r))"
       
   135 using assms
       
   136 apply(induct r arbitrary: v rule: simp.induct)
       
   137 apply(auto simp add: simp_SEQ_simps simp_ALT_simps intro: Prf.intros)
       
   138 using Prf_elims(3) apply blast
       
   139 apply(erule Prf_elims)
       
   140 apply(simp)
       
   141 apply(clarify)
       
   142 apply(blast)
       
   143 apply(simp)
       
   144 apply(erule Prf_elims)
       
   145 apply(simp)
       
   146 apply(simp)
       
   147 apply(clarify)
       
   148 apply(blast)
       
   149 apply(erule Prf_elims)
       
   150 apply(case_tac v)
       
   151 apply(simp_all)
       
   152 apply(rule Prf.intros)
       
   153 apply(clarify)
       
   154 apply(simp)
       
   155 apply(case_tac v)
       
   156 apply(simp_all)
       
   157 apply(rule Prf.intros)
       
   158 apply(clarify)
       
   159 apply(simp)
       
   160 apply(erule Prf_elims)
       
   161 apply(simp)
       
   162 apply(rule Prf.intros)
       
   163 apply(simp)
       
   164 apply(simp)
       
   165 apply(rule Prf.intros)
       
   166 apply(simp)
       
   167 apply(erule Prf_elims)
       
   168 apply(simp)
       
   169 apply(blast)
       
   170 apply(rule Prf.intros)
       
   171 apply(erule Prf_elims)
       
   172 apply(simp)
       
   173 apply(rule Prf.intros)
       
   174 apply(erule Prf_elims)
       
   175 apply(simp)
       
   176 apply(rule Prf.intros)
       
   177 apply(erule Prf_elims)
       
   178 apply(simp)
       
   179 apply(clarify)
       
   180 apply(blast)
       
   181 apply(rule Prf.intros)
       
   182 apply(blast)
       
   183 using Prf.intros(4) apply blast
       
   184 apply(erule Prf_elims)
       
   185 apply(simp)
       
   186 apply(clarify)
       
   187 apply(blast)
       
   188 apply(rule Prf.intros)
       
   189 using Prf.intros(4) apply blast
       
   190 apply blast
       
   191 apply(erule Prf_elims)
       
   192 apply(case_tac v)
       
   193 apply(simp_all)
       
   194 apply(rule Prf.intros)
       
   195 apply(clarify)
       
   196 apply(simp)
       
   197 apply(clarify)
       
   198 apply(blast)
       
   199 apply(erule Prf_elims)
       
   200 apply(case_tac v)
       
   201 apply(simp_all)
       
   202 apply(rule Prf.intros)
       
   203 apply(clarify)
       
   204 apply(simp)
       
   205 apply(simp)
       
   206 done
       
   207 
       
   208 lemma Posix_simp_nullable:
       
   209   assumes "nullable r" "[] \<in> (fst (simp r)) \<rightarrow> v"
       
   210   shows "((snd (simp r)) v) = mkeps r"
       
   211 using assms 
       
   212 apply(induct r arbitrary: v)
       
   213 apply(auto simp add: simp_SEQ_simps simp_ALT_simps)
       
   214 apply(erule Posix_elims)
       
   215 apply(simp)
       
   216 apply(erule Posix_elims)
       
   217 apply(clarify)
       
   218 using Posix.intros(1) apply blast
       
   219 using Posix.intros(1) apply blast
       
   220 using Posix.intros(1) apply blast
       
   221 apply(erule Posix_elims)
       
   222 apply(simp)
       
   223 apply(erule Posix_elims)
       
   224 apply (metis L_fst_simp nullable.simps(1) nullable_correctness)
       
   225 apply(erule Posix_elims)
       
   226 apply(clarify)
       
   227 apply(simp)
       
   228 apply(clarify)
       
   229 apply(simp)
       
   230 apply(simp only: L_fst_simp[symmetric])
       
   231 apply (simp add: nullable_correctness)
       
   232 apply(erule Posix_elims)
       
   233 using L_fst_simp Posix1(1) nullable_correctness apply blast
       
   234 apply (metis L.simps(1) L_fst_simp Prf_flat_L empty_iff mkeps_nullable)
       
   235 apply(erule Posix_elims)
       
   236 apply(clarify)
       
   237 apply(simp)
       
   238 apply(simp only: L_fst_simp[symmetric])
       
   239 apply (simp add: nullable_correctness)
       
   240 apply(erule Posix_elims)
       
   241 apply(clarify)
       
   242 apply(simp)
       
   243 using L_fst_simp Posix1(1) nullable_correctness apply blast
       
   244 apply(simp)
       
   245 apply(erule Posix_elims)
       
   246 apply(clarify)
       
   247 apply(simp)
       
   248 using Posix1(2) apply auto[1]
       
   249 apply(simp)
       
   250 done
       
   251 
       
   252 lemma Posix_simp:
       
   253   assumes "s \<in> (fst (simp r)) \<rightarrow> v" 
       
   254   shows "s \<in> r \<rightarrow> ((snd (simp r)) v)"
       
   255 using assms
       
   256 apply(induct r arbitrary: s v rule: rexp.induct) 
       
   257 apply(auto split: if_splits simp add: simp_SEQ_simps simp_ALT_simps)
       
   258 prefer 3
       
   259 apply(erule Posix_elims)
       
   260 apply(clarify)
       
   261 apply(simp)
       
   262 apply(rule Posix.intros)
       
   263 apply(blast)
       
   264 apply(blast)
       
   265 apply(auto)[1]
       
   266 apply(simp add: L_fst_simp[symmetric])
       
   267 apply(auto)[1]
       
   268 prefer 3
       
   269 apply(rule Posix.intros)
       
   270 apply(blast)
       
   271 apply (metis L.simps(1) L_fst_simp equals0D)
       
   272 prefer 3
       
   273 apply(rule Posix.intros)
       
   274 apply(blast)
       
   275 prefer 3
       
   276 apply(erule Posix_elims)
       
   277 apply(clarify)
       
   278 apply(simp)
       
   279 apply(rule Posix.intros)
       
   280 apply(blast)
       
   281 apply(simp)
       
   282 apply(rule Posix.intros)
       
   283 apply(blast)
       
   284 apply(simp add: L_fst_simp[symmetric])
       
   285 apply(subst append.simps[symmetric])
       
   286 apply(rule Posix.intros)
       
   287 prefer 2
       
   288 apply(blast)
       
   289 prefer 2
       
   290 apply(auto)[1]
       
   291 apply (metis L_fst_simp Posix_elims(2) lex_correct3a)
       
   292 apply(subst Posix_simp_nullable)
       
   293 using Posix.intros(1) Posix1(1) nullable_correctness apply blast
       
   294 apply(simp)
       
   295 apply(rule Posix.intros)
       
   296 apply(rule Posix_mkeps)
       
   297 using Posix.intros(1) Posix1(1) nullable_correctness apply blast
       
   298 apply(subst append_Nil2[symmetric])
       
   299 apply(rule Posix.intros)
       
   300 apply(blast)
       
   301 apply(subst Posix_simp_nullable)
       
   302 using Posix.intros(1) Posix1(1) nullable_correctness apply blast
       
   303 apply(simp)
       
   304 apply(rule Posix.intros)
       
   305 apply(rule Posix_mkeps)
       
   306 using Posix.intros(1) Posix1(1) nullable_correctness apply blast
       
   307 apply(auto)
       
   308 done
       
   309 
       
   310 lemma slexer_correctness:
       
   311   shows "slexer r s = lexer r s"
       
   312 apply(induct s arbitrary: r)
       
   313 apply(simp)
       
   314 apply(simp)
       
   315 apply(auto split: option.split prod.split)
       
   316 apply (metis L_fst_simp fst_conv lex_correct1a)
       
   317 using L_fst_simp lex_correct1a apply fastforce
       
   318 by (metis Posix_determ Posix_simp fst_conv lex_correct1 lex_correct3a option.distinct(1) option.inject snd_conv)
       
   319 
       
   320 
       
   321 
       
   322 end