src/ZF/Constructible/Rec_Separation.thy
changeset 13363 c26eeb000470
parent 13352 3cd767f8d78b
child 13385 31df66ca0780
equal deleted inserted replaced
13362:cd7f9ea58338 13363:c26eeb000470
     1 header{*Separation for the Absoluteness of Recursion*}
     1 header{*Separation for Facts About Recursion*}
     2 
     2 
     3 theory Rec_Separation = Separation:
     3 theory Rec_Separation = Separation + Datatype_absolute:
     4 
     4 
     5 text{*This theory proves all instances needed for locales @{text
     5 text{*This theory proves all instances needed for locales @{text
     6 "M_trancl"}, @{text "M_wfrank"} and @{text "M_datatypes"}*}
     6 "M_trancl"}, @{text "M_wfrank"} and @{text "M_datatypes"}*}
       
     7 
       
     8 lemma eq_succ_imp_lt: "[|i = succ(j); Ord(i)|] ==> j<i"
       
     9 by simp 
     7 
    10 
     8 subsection{*The Locale @{text "M_trancl"}*}
    11 subsection{*The Locale @{text "M_trancl"}*}
     9 
    12 
    10 subsubsection{*Separation for Reflexive/Transitive Closure*}
    13 subsubsection{*Separation for Reflexive/Transitive Closure*}
    11 
    14 
   192 apply (rule_tac env = "[w,u,r,Z]" in mem_iff_sats) 
   195 apply (rule_tac env = "[w,u,r,Z]" in mem_iff_sats) 
   193 apply (rule sep_rules tran_closure_iff_sats | simp)+
   196 apply (rule sep_rules tran_closure_iff_sats | simp)+
   194 apply (simp_all add: succ_Un_distrib [symmetric])
   197 apply (simp_all add: succ_Un_distrib [symmetric])
   195 done
   198 done
   196 
   199 
       
   200 
       
   201 subsubsection{*Instantiating the locale @{text M_trancl}*}
       
   202 ML
       
   203 {*
       
   204 val rtrancl_separation = thm "rtrancl_separation";
       
   205 val wellfounded_trancl_separation = thm "wellfounded_trancl_separation";
       
   206 
       
   207 
       
   208 val m_trancl = [rtrancl_separation, wellfounded_trancl_separation];
       
   209 
       
   210 fun trancl_L th =
       
   211     kill_flex_triv_prems (m_trancl MRS (axioms_L th));
       
   212 
       
   213 bind_thm ("iterates_abs", trancl_L (thm "M_trancl.iterates_abs"));
       
   214 bind_thm ("rtran_closure_rtrancl", trancl_L (thm "M_trancl.rtran_closure_rtrancl"));
       
   215 bind_thm ("rtrancl_closed", trancl_L (thm "M_trancl.rtrancl_closed"));
       
   216 bind_thm ("rtrancl_abs", trancl_L (thm "M_trancl.rtrancl_abs"));
       
   217 bind_thm ("trancl_closed", trancl_L (thm "M_trancl.trancl_closed"));
       
   218 bind_thm ("trancl_abs", trancl_L (thm "M_trancl.trancl_abs"));
       
   219 bind_thm ("wellfounded_on_trancl", trancl_L (thm "M_trancl.wellfounded_on_trancl"));
       
   220 bind_thm ("wellfounded_trancl", trancl_L (thm "M_trancl.wellfounded_trancl"));
       
   221 bind_thm ("wfrec_relativize", trancl_L (thm "M_trancl.wfrec_relativize"));
       
   222 bind_thm ("trans_wfrec_relativize", trancl_L (thm "M_trancl.trans_wfrec_relativize"));
       
   223 bind_thm ("trans_wfrec_abs", trancl_L (thm "M_trancl.trans_wfrec_abs"));
       
   224 bind_thm ("trans_eq_pair_wfrec_iff", trancl_L (thm "M_trancl.trans_eq_pair_wfrec_iff"));
       
   225 bind_thm ("eq_pair_wfrec_iff", trancl_L (thm "M_trancl.eq_pair_wfrec_iff"));
       
   226 *}
       
   227 
       
   228 declare rtrancl_closed [intro,simp]
       
   229 declare rtrancl_abs [simp]
       
   230 declare trancl_closed [intro,simp]
       
   231 declare trancl_abs [simp]
       
   232 
       
   233 
   197 subsection{*Well-Founded Recursion!*}
   234 subsection{*Well-Founded Recursion!*}
   198 
   235 
   199 (* M_is_recfun :: "[i=>o, [i,i,i]=>o, i, i, i] => o"
   236 (* M_is_recfun :: "[i=>o, [i,i,i]=>o, i, i, i] => o"
   200    "M_is_recfun(M,MH,r,a,f) == 
   237    "M_is_recfun(M,MH,r,a,f) == 
   201      \<forall>z[M]. z \<in> f <-> 
   238      \<forall>z[M]. z \<in> f <-> 
   273 apply (simp (no_asm_use) only: M_is_recfun_def setclass_simps)
   310 apply (simp (no_asm_use) only: M_is_recfun_def setclass_simps)
   274 apply (intro FOL_reflections function_reflections 
   311 apply (intro FOL_reflections function_reflections 
   275              restriction_reflection MH_reflection)  
   312              restriction_reflection MH_reflection)  
   276 done
   313 done
   277 
   314 
   278 subsection{*Separation for  @{term "wfrank"}*}
   315 text{*Currently, @{text sats}-theorems for higher-order operators don't seem
       
   316 useful.  Reflection theorems do work, though.  This one avoids the repetition
       
   317 of the @{text MH}-term.*}
       
   318 theorem is_wfrec_reflection:
       
   319   assumes MH_reflection:
       
   320     "!!f g h. REFLECTS[\<lambda>x. MH(L, f(x), g(x), h(x)), 
       
   321                      \<lambda>i x. MH(**Lset(i), f(x), g(x), h(x))]"
       
   322   shows "REFLECTS[\<lambda>x. is_wfrec(L, MH(L), f(x), g(x), h(x)), 
       
   323                \<lambda>i x. is_wfrec(**Lset(i), MH(**Lset(i)), f(x), g(x), h(x))]"
       
   324 apply (simp (no_asm_use) only: is_wfrec_def setclass_simps)
       
   325 apply (intro FOL_reflections MH_reflection is_recfun_reflection)  
       
   326 done
       
   327 
       
   328 subsection{*The Locale @{text "M_wfrank"}*}
       
   329 
       
   330 subsubsection{*Separation for @{term "wfrank"}*}
   279 
   331 
   280 lemma wfrank_Reflects:
   332 lemma wfrank_Reflects:
   281  "REFLECTS[\<lambda>x. \<forall>rplus[L]. tran_closure(L,r,rplus) -->
   333  "REFLECTS[\<lambda>x. \<forall>rplus[L]. tran_closure(L,r,rplus) -->
   282               ~ (\<exists>f[L]. M_is_recfun(L, %x f y. is_range(L,f,y), rplus, x, f)),
   334               ~ (\<exists>f[L]. M_is_recfun(L, %x f y. is_range(L,f,y), rplus, x, f)),
   283       \<lambda>i x. \<forall>rplus \<in> Lset(i). tran_closure(**Lset(i),r,rplus) -->
   335       \<lambda>i x. \<forall>rplus \<in> Lset(i). tran_closure(**Lset(i),r,rplus) -->
   303 apply (rule sep_rules is_recfun_iff_sats | simp)+
   355 apply (rule sep_rules is_recfun_iff_sats | simp)+
   304 apply (simp_all add: succ_Un_distrib [symmetric])
   356 apply (simp_all add: succ_Un_distrib [symmetric])
   305 done
   357 done
   306 
   358 
   307 
   359 
   308 subsection{*Replacement for @{term "wfrank"}*}
   360 subsubsection{*Replacement for @{term "wfrank"}*}
   309 
   361 
   310 lemma wfrank_replacement_Reflects:
   362 lemma wfrank_replacement_Reflects:
   311  "REFLECTS[\<lambda>z. \<exists>x[L]. x \<in> A & 
   363  "REFLECTS[\<lambda>z. \<exists>x[L]. x \<in> A & 
   312         (\<forall>rplus[L]. tran_closure(L,r,rplus) -->
   364         (\<forall>rplus[L]. tran_closure(L,r,rplus) -->
   313          (\<exists>y[L]. \<exists>f[L]. pair(L,x,y,z)  & 
   365          (\<exists>y[L]. \<exists>f[L]. pair(L,x,y,z)  & 
   345 apply (rule sep_rules tran_closure_iff_sats is_recfun_iff_sats | simp)+
   397 apply (rule sep_rules tran_closure_iff_sats is_recfun_iff_sats | simp)+
   346 apply (simp_all add: succ_Un_distrib [symmetric])
   398 apply (simp_all add: succ_Un_distrib [symmetric])
   347 done
   399 done
   348 
   400 
   349 
   401 
   350 subsection{*Separation for  @{term "wfrank"}*}
   402 subsubsection{*Separation for Proving @{text Ord_wfrank_range}*}
   351 
   403 
   352 lemma Ord_wfrank_Reflects:
   404 lemma Ord_wfrank_Reflects:
   353  "REFLECTS[\<lambda>x. \<forall>rplus[L]. tran_closure(L,r,rplus) --> 
   405  "REFLECTS[\<lambda>x. \<forall>rplus[L]. tran_closure(L,r,rplus) --> 
   354           ~ (\<forall>f[L]. \<forall>rangef[L]. 
   406           ~ (\<forall>f[L]. \<forall>rangef[L]. 
   355              is_range(L,f,rangef) -->
   407              is_range(L,f,rangef) -->
   385 apply (rule sep_rules is_recfun_iff_sats | simp)+
   437 apply (rule sep_rules is_recfun_iff_sats | simp)+
   386 apply (simp_all add: succ_Un_distrib [symmetric])
   438 apply (simp_all add: succ_Un_distrib [symmetric])
   387 done
   439 done
   388 
   440 
   389 
   441 
       
   442 subsubsection{*Instantiating the locale @{text M_wfrank}*}
       
   443 ML
       
   444 {*
       
   445 val wfrank_separation = thm "wfrank_separation";
       
   446 val wfrank_strong_replacement = thm "wfrank_strong_replacement";
       
   447 val Ord_wfrank_separation = thm "Ord_wfrank_separation";
       
   448 
       
   449 val m_wfrank = 
       
   450     [wfrank_separation, wfrank_strong_replacement, Ord_wfrank_separation];
       
   451 
       
   452 fun wfrank_L th =
       
   453     kill_flex_triv_prems (m_wfrank MRS (trancl_L th));
       
   454 
       
   455 
       
   456 
       
   457 bind_thm ("iterates_closed", wfrank_L (thm "M_wfrank.iterates_closed"));
       
   458 bind_thm ("exists_wfrank", wfrank_L (thm "M_wfrank.exists_wfrank"));
       
   459 bind_thm ("M_wellfoundedrank", wfrank_L (thm "M_wfrank.M_wellfoundedrank"));
       
   460 bind_thm ("Ord_wfrank_range", wfrank_L (thm "M_wfrank.Ord_wfrank_range"));
       
   461 bind_thm ("Ord_range_wellfoundedrank", wfrank_L (thm "M_wfrank.Ord_range_wellfoundedrank"));
       
   462 bind_thm ("function_wellfoundedrank", wfrank_L (thm "M_wfrank.function_wellfoundedrank"));
       
   463 bind_thm ("domain_wellfoundedrank", wfrank_L (thm "M_wfrank.domain_wellfoundedrank"));
       
   464 bind_thm ("wellfoundedrank_type", wfrank_L (thm "M_wfrank.wellfoundedrank_type"));
       
   465 bind_thm ("Ord_wellfoundedrank", wfrank_L (thm "M_wfrank.Ord_wellfoundedrank"));
       
   466 bind_thm ("wellfoundedrank_eq", wfrank_L (thm "M_wfrank.wellfoundedrank_eq"));
       
   467 bind_thm ("wellfoundedrank_lt", wfrank_L (thm "M_wfrank.wellfoundedrank_lt"));
       
   468 bind_thm ("wellfounded_imp_subset_rvimage", wfrank_L (thm "M_wfrank.wellfounded_imp_subset_rvimage"));
       
   469 bind_thm ("wellfounded_imp_wf", wfrank_L (thm "M_wfrank.wellfounded_imp_wf"));
       
   470 bind_thm ("wellfounded_on_imp_wf_on", wfrank_L (thm "M_wfrank.wellfounded_on_imp_wf_on"));
       
   471 bind_thm ("wf_abs", wfrank_L (thm "M_wfrank.wf_abs"));
       
   472 bind_thm ("wf_on_abs", wfrank_L (thm "M_wfrank.wf_on_abs"));
       
   473 bind_thm ("wfrec_replacement_iff", wfrank_L (thm "M_wfrank.wfrec_replacement_iff"));
       
   474 bind_thm ("trans_wfrec_closed", wfrank_L (thm "M_wfrank.trans_wfrec_closed"));
       
   475 bind_thm ("wfrec_closed", wfrank_L (thm "M_wfrank.wfrec_closed"));
       
   476 *}
       
   477 
       
   478 declare iterates_closed [intro,simp]
       
   479 declare Ord_wfrank_range [rule_format]
       
   480 declare wf_abs [simp]
       
   481 declare wf_on_abs [simp]
       
   482 
       
   483 
       
   484 subsection{*For Datatypes*}
       
   485 
       
   486 subsubsection{*Binary Products, Internalized*}
       
   487 
       
   488 constdefs cartprod_fm :: "[i,i,i]=>i"
       
   489 (* "cartprod(M,A,B,z) == 
       
   490 	\<forall>u[M]. u \<in> z <-> (\<exists>x[M]. x\<in>A & (\<exists>y[M]. y\<in>B & pair(M,x,y,u)))" *)
       
   491     "cartprod_fm(A,B,z) == 
       
   492        Forall(Iff(Member(0,succ(z)),
       
   493                   Exists(And(Member(0,succ(succ(A))),
       
   494                          Exists(And(Member(0,succ(succ(succ(B)))),
       
   495                                     pair_fm(1,0,2)))))))"
       
   496 
       
   497 lemma cartprod_type [TC]:
       
   498      "[| x \<in> nat; y \<in> nat; z \<in> nat |] ==> cartprod_fm(x,y,z) \<in> formula"
       
   499 by (simp add: cartprod_fm_def) 
       
   500 
       
   501 lemma arity_cartprod_fm [simp]:
       
   502      "[| x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   503       ==> arity(cartprod_fm(x,y,z)) = succ(x) \<union> succ(y) \<union> succ(z)"
       
   504 by (simp add: cartprod_fm_def succ_Un_distrib [symmetric] Un_ac) 
       
   505 
       
   506 lemma sats_cartprod_fm [simp]:
       
   507    "[| x \<in> nat; y \<in> nat; z \<in> nat; env \<in> list(A)|]
       
   508     ==> sats(A, cartprod_fm(x,y,z), env) <-> 
       
   509         cartprod(**A, nth(x,env), nth(y,env), nth(z,env))"
       
   510 by (simp add: cartprod_fm_def cartprod_def)
       
   511 
       
   512 lemma cartprod_iff_sats:
       
   513       "[| nth(i,env) = x; nth(j,env) = y; nth(k,env) = z; 
       
   514           i \<in> nat; j \<in> nat; k \<in> nat; env \<in> list(A)|]
       
   515        ==> cartprod(**A, x, y, z) <-> sats(A, cartprod_fm(i,j,k), env)"
       
   516 by (simp add: sats_cartprod_fm)
       
   517 
       
   518 theorem cartprod_reflection:
       
   519      "REFLECTS[\<lambda>x. cartprod(L,f(x),g(x),h(x)), 
       
   520                \<lambda>i x. cartprod(**Lset(i),f(x),g(x),h(x))]"
       
   521 apply (simp only: cartprod_def setclass_simps)
       
   522 apply (intro FOL_reflections pair_reflection)  
       
   523 done
       
   524 
       
   525 
       
   526 subsubsection{*Binary Sums, Internalized*}
       
   527 
       
   528 (* "is_sum(M,A,B,Z) == 
       
   529        \<exists>A0[M]. \<exists>n1[M]. \<exists>s1[M]. \<exists>B1[M]. 
       
   530          3      2       1        0
       
   531        number1(M,n1) & cartprod(M,n1,A,A0) & upair(M,n1,n1,s1) &
       
   532        cartprod(M,s1,B,B1) & union(M,A0,B1,Z)"  *)
       
   533 constdefs sum_fm :: "[i,i,i]=>i"
       
   534     "sum_fm(A,B,Z) == 
       
   535        Exists(Exists(Exists(Exists(
       
   536 	And(number1_fm(2),
       
   537             And(cartprod_fm(2,A#+4,3),
       
   538                 And(upair_fm(2,2,1),
       
   539                     And(cartprod_fm(1,B#+4,0), union_fm(3,0,Z#+4)))))))))"
       
   540 
       
   541 lemma sum_type [TC]:
       
   542      "[| x \<in> nat; y \<in> nat; z \<in> nat |] ==> sum_fm(x,y,z) \<in> formula"
       
   543 by (simp add: sum_fm_def) 
       
   544 
       
   545 lemma arity_sum_fm [simp]:
       
   546      "[| x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   547       ==> arity(sum_fm(x,y,z)) = succ(x) \<union> succ(y) \<union> succ(z)"
       
   548 by (simp add: sum_fm_def succ_Un_distrib [symmetric] Un_ac) 
       
   549 
       
   550 lemma sats_sum_fm [simp]:
       
   551    "[| x \<in> nat; y \<in> nat; z \<in> nat; env \<in> list(A)|]
       
   552     ==> sats(A, sum_fm(x,y,z), env) <-> 
       
   553         is_sum(**A, nth(x,env), nth(y,env), nth(z,env))"
       
   554 by (simp add: sum_fm_def is_sum_def)
       
   555 
       
   556 lemma sum_iff_sats:
       
   557       "[| nth(i,env) = x; nth(j,env) = y; nth(k,env) = z; 
       
   558           i \<in> nat; j \<in> nat; k \<in> nat; env \<in> list(A)|]
       
   559        ==> is_sum(**A, x, y, z) <-> sats(A, sum_fm(i,j,k), env)"
       
   560 by simp
       
   561 
       
   562 theorem sum_reflection:
       
   563      "REFLECTS[\<lambda>x. is_sum(L,f(x),g(x),h(x)), 
       
   564                \<lambda>i x. is_sum(**Lset(i),f(x),g(x),h(x))]"
       
   565 apply (simp only: is_sum_def setclass_simps)
       
   566 apply (intro FOL_reflections function_reflections cartprod_reflection)  
       
   567 done
       
   568 
       
   569 
       
   570 subsubsection{*The List Functor, Internalized*}
       
   571 
       
   572 constdefs list_functor_fm :: "[i,i,i]=>i"
       
   573 (* "is_list_functor(M,A,X,Z) == 
       
   574         \<exists>n1[M]. \<exists>AX[M]. 
       
   575          number1(M,n1) & cartprod(M,A,X,AX) & is_sum(M,n1,AX,Z)" *)
       
   576     "list_functor_fm(A,X,Z) == 
       
   577        Exists(Exists(
       
   578 	And(number1_fm(1),
       
   579             And(cartprod_fm(A#+2,X#+2,0), sum_fm(1,0,Z#+2)))))"
       
   580 
       
   581 lemma list_functor_type [TC]:
       
   582      "[| x \<in> nat; y \<in> nat; z \<in> nat |] ==> list_functor_fm(x,y,z) \<in> formula"
       
   583 by (simp add: list_functor_fm_def) 
       
   584 
       
   585 lemma arity_list_functor_fm [simp]:
       
   586      "[| x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   587       ==> arity(list_functor_fm(x,y,z)) = succ(x) \<union> succ(y) \<union> succ(z)"
       
   588 by (simp add: list_functor_fm_def succ_Un_distrib [symmetric] Un_ac) 
       
   589 
       
   590 lemma sats_list_functor_fm [simp]:
       
   591    "[| x \<in> nat; y \<in> nat; z \<in> nat; env \<in> list(A)|]
       
   592     ==> sats(A, list_functor_fm(x,y,z), env) <-> 
       
   593         is_list_functor(**A, nth(x,env), nth(y,env), nth(z,env))"
       
   594 by (simp add: list_functor_fm_def is_list_functor_def)
       
   595 
       
   596 lemma list_functor_iff_sats:
       
   597   "[| nth(i,env) = x; nth(j,env) = y; nth(k,env) = z; 
       
   598       i \<in> nat; j \<in> nat; k \<in> nat; env \<in> list(A)|]
       
   599    ==> is_list_functor(**A, x, y, z) <-> sats(A, list_functor_fm(i,j,k), env)"
       
   600 by simp
       
   601 
       
   602 theorem list_functor_reflection:
       
   603      "REFLECTS[\<lambda>x. is_list_functor(L,f(x),g(x),h(x)), 
       
   604                \<lambda>i x. is_list_functor(**Lset(i),f(x),g(x),h(x))]"
       
   605 apply (simp only: is_list_functor_def setclass_simps)
       
   606 apply (intro FOL_reflections number1_reflection
       
   607              cartprod_reflection sum_reflection)  
       
   608 done
       
   609 
       
   610 subsubsection{*The Operator @{term quasinat}*}
       
   611 
       
   612 (* "is_quasinat(M,z) == empty(M,z) | (\<exists>m[M]. successor(M,m,z))" *)
       
   613 constdefs quasinat_fm :: "i=>i"
       
   614     "quasinat_fm(z) == Or(empty_fm(z), Exists(succ_fm(0,succ(z))))"
       
   615 
       
   616 lemma quasinat_type [TC]:
       
   617      "x \<in> nat ==> quasinat_fm(x) \<in> formula"
       
   618 by (simp add: quasinat_fm_def) 
       
   619 
       
   620 lemma arity_quasinat_fm [simp]:
       
   621      "x \<in> nat ==> arity(quasinat_fm(x)) = succ(x)"
       
   622 by (simp add: quasinat_fm_def succ_Un_distrib [symmetric] Un_ac) 
       
   623 
       
   624 lemma sats_quasinat_fm [simp]:
       
   625    "[| x \<in> nat; env \<in> list(A)|]
       
   626     ==> sats(A, quasinat_fm(x), env) <-> is_quasinat(**A, nth(x,env))"
       
   627 by (simp add: quasinat_fm_def is_quasinat_def)
       
   628 
       
   629 lemma quasinat_iff_sats:
       
   630       "[| nth(i,env) = x; nth(j,env) = y; 
       
   631           i \<in> nat; env \<in> list(A)|]
       
   632        ==> is_quasinat(**A, x) <-> sats(A, quasinat_fm(i), env)"
       
   633 by simp
       
   634 
       
   635 theorem quasinat_reflection:
       
   636      "REFLECTS[\<lambda>x. is_quasinat(L,f(x)), 
       
   637                \<lambda>i x. is_quasinat(**Lset(i),f(x))]"
       
   638 apply (simp only: is_quasinat_def setclass_simps)
       
   639 apply (intro FOL_reflections function_reflections)  
       
   640 done
       
   641 
       
   642 
       
   643 subsubsection{*The Operator @{term is_nat_case}*}
       
   644 
       
   645 (* is_nat_case :: "[i=>o, i, [i,i]=>o, i, i] => o"
       
   646     "is_nat_case(M, a, is_b, k, z) == 
       
   647        (empty(M,k) --> z=a) &
       
   648        (\<forall>m[M]. successor(M,m,k) --> is_b(m,z)) &
       
   649        (is_quasinat(M,k) | empty(M,z))" *)
       
   650 text{*The formula @{term is_b} has free variables 1 and 0.*}
       
   651 constdefs is_nat_case_fm :: "[i, [i,i]=>i, i, i]=>i"
       
   652  "is_nat_case_fm(a,is_b,k,z) == 
       
   653     And(Implies(empty_fm(k), Equal(z,a)),
       
   654         And(Forall(Implies(succ_fm(0,succ(k)), 
       
   655                    Forall(Implies(Equal(0,succ(succ(z))), is_b(1,0))))),
       
   656             Or(quasinat_fm(k), empty_fm(z))))"
       
   657 
       
   658 lemma is_nat_case_type [TC]:
       
   659      "[| is_b(1,0) \<in> formula;  
       
   660          x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   661       ==> is_nat_case_fm(x,is_b,y,z) \<in> formula"
       
   662 by (simp add: is_nat_case_fm_def) 
       
   663 
       
   664 lemma arity_is_nat_case_fm [simp]:
       
   665      "[| is_b(1,0) \<in> formula; x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   666       ==> arity(is_nat_case_fm(x,is_b,y,z)) = 
       
   667           succ(x) \<union> succ(y) \<union> succ(z) \<union> (arity(is_b(1,0)) #- 2)" 
       
   668 apply (subgoal_tac "arity(is_b(1,0)) \<in> nat")  
       
   669 apply typecheck
       
   670 (*FIXME: could nat_diff_split work?*)
       
   671 apply (auto simp add: diff_def raw_diff_succ is_nat_case_fm_def nat_imp_quasinat
       
   672                  succ_Un_distrib [symmetric] Un_ac
       
   673                  split: split_nat_case) 
       
   674 done
       
   675 
       
   676 lemma sats_is_nat_case_fm:
       
   677   assumes is_b_iff_sats: 
       
   678       "!!a b. [| a \<in> A; b \<in> A|] 
       
   679               ==> is_b(a,b) <-> sats(A, p(1,0), Cons(b, Cons(a,env)))"
       
   680   shows 
       
   681       "[|x \<in> nat; y \<in> nat; z < length(env); env \<in> list(A)|]
       
   682        ==> sats(A, is_nat_case_fm(x,p,y,z), env) <-> 
       
   683            is_nat_case(**A, nth(x,env), is_b, nth(y,env), nth(z,env))"
       
   684 apply (frule lt_length_in_nat, assumption)  
       
   685 apply (simp add: is_nat_case_fm_def is_nat_case_def is_b_iff_sats [THEN iff_sym])
       
   686 done
       
   687 
       
   688 lemma is_nat_case_iff_sats:
       
   689   "[| (!!a b. [| a \<in> A; b \<in> A|] 
       
   690               ==> is_b(a,b) <-> sats(A, p(1,0), Cons(b, Cons(a,env))));
       
   691       nth(i,env) = x; nth(j,env) = y; nth(k,env) = z; 
       
   692       i \<in> nat; j \<in> nat; k < length(env); env \<in> list(A)|]
       
   693    ==> is_nat_case(**A, x, is_b, y, z) <-> sats(A, is_nat_case_fm(i,p,j,k), env)" 
       
   694 by (simp add: sats_is_nat_case_fm [of A is_b])
       
   695 
       
   696 
       
   697 text{*The second argument of @{term is_b} gives it direct access to @{term x},
       
   698   which is essential for handling free variable references.  Without this 
       
   699   argument, we cannot prove reflection for @{term iterates_MH}.*}
       
   700 theorem is_nat_case_reflection:
       
   701   assumes is_b_reflection:
       
   702     "!!h f g. REFLECTS[\<lambda>x. is_b(L, h(x), f(x), g(x)), 
       
   703                      \<lambda>i x. is_b(**Lset(i), h(x), f(x), g(x))]"
       
   704   shows "REFLECTS[\<lambda>x. is_nat_case(L, f(x), is_b(L,x), g(x), h(x)), 
       
   705                \<lambda>i x. is_nat_case(**Lset(i), f(x), is_b(**Lset(i), x), g(x), h(x))]"
       
   706 apply (simp (no_asm_use) only: is_nat_case_def setclass_simps)
       
   707 apply (intro FOL_reflections function_reflections 
       
   708              restriction_reflection is_b_reflection quasinat_reflection)  
       
   709 done
       
   710 
       
   711 
       
   712 
       
   713 subsection{*The Operator @{term iterates_MH}, Needed for Iteration*}
       
   714 
       
   715 (*  iterates_MH :: "[i=>o, [i,i]=>o, i, i, i, i] => o"
       
   716    "iterates_MH(M,isF,v,n,g,z) ==
       
   717         is_nat_case(M, v, \<lambda>m u. \<exists>gm[M]. fun_apply(M,g,m,gm) & isF(gm,u),
       
   718                     n, z)" *)
       
   719 constdefs iterates_MH_fm :: "[[i,i]=>i, i, i, i, i]=>i"
       
   720  "iterates_MH_fm(isF,v,n,g,z) == 
       
   721     is_nat_case_fm(v, 
       
   722       \<lambda>m u. Exists(And(fun_apply_fm(succ(succ(succ(g))),succ(m),0), 
       
   723                      Forall(Implies(Equal(0,succ(succ(u))), isF(1,0))))), 
       
   724       n, z)"
       
   725 
       
   726 lemma iterates_MH_type [TC]:
       
   727      "[| p(1,0) \<in> formula;  
       
   728          v \<in> nat; x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   729       ==> iterates_MH_fm(p,v,x,y,z) \<in> formula"
       
   730 by (simp add: iterates_MH_fm_def) 
       
   731 
       
   732 
       
   733 lemma arity_iterates_MH_fm [simp]:
       
   734      "[| p(1,0) \<in> formula; 
       
   735          v \<in> nat; x \<in> nat; y \<in> nat; z \<in> nat |] 
       
   736       ==> arity(iterates_MH_fm(p,v,x,y,z)) = 
       
   737           succ(v) \<union> succ(x) \<union> succ(y) \<union> succ(z) \<union> (arity(p(1,0)) #- 4)"
       
   738 apply (subgoal_tac "arity(p(1,0)) \<in> nat")
       
   739 apply typecheck
       
   740 apply (simp add: nat_imp_quasinat iterates_MH_fm_def Un_ac
       
   741             split: split_nat_case, clarify)
       
   742 apply (rename_tac i j)
       
   743 apply (drule eq_succ_imp_eq_m1, simp) 
       
   744 apply (drule eq_succ_imp_eq_m1, simp)
       
   745 apply (simp add: diff_Un_distrib succ_Un_distrib Un_ac diff_diff_left)
       
   746 done
       
   747 
       
   748 lemma sats_iterates_MH_fm:
       
   749   assumes is_F_iff_sats: 
       
   750       "!!a b c d. [| a \<in> A; b \<in> A; c \<in> A; d \<in> A|] 
       
   751               ==> is_F(a,b) <->
       
   752                   sats(A, p(1,0), Cons(b, Cons(a, Cons(c, Cons(d,env)))))"
       
   753   shows 
       
   754       "[|v \<in> nat; x \<in> nat; y \<in> nat; z < length(env); env \<in> list(A)|]
       
   755        ==> sats(A, iterates_MH_fm(p,v,x,y,z), env) <-> 
       
   756            iterates_MH(**A, is_F, nth(v,env), nth(x,env), nth(y,env), nth(z,env))"
       
   757 by (simp add: iterates_MH_fm_def iterates_MH_def sats_is_nat_case_fm 
       
   758               is_F_iff_sats [symmetric])
       
   759 
       
   760 lemma iterates_MH_iff_sats:
       
   761   "[| (!!a b c d. [| a \<in> A; b \<in> A; c \<in> A; d \<in> A|] 
       
   762               ==> is_F(a,b) <->
       
   763                   sats(A, p(1,0), Cons(b, Cons(a, Cons(c, Cons(d,env))))));
       
   764       nth(i',env) = v; nth(i,env) = x; nth(j,env) = y; nth(k,env) = z; 
       
   765       i' \<in> nat; i \<in> nat; j \<in> nat; k < length(env); env \<in> list(A)|]
       
   766    ==> iterates_MH(**A, is_F, v, x, y, z) <-> 
       
   767        sats(A, iterates_MH_fm(p,i',i,j,k), env)"
       
   768 apply (rule iff_sym) 
       
   769 apply (rule iff_trans) 
       
   770 apply (rule sats_iterates_MH_fm [of A is_F], blast, simp_all) 
       
   771 done
       
   772 
       
   773 theorem iterates_MH_reflection:
       
   774   assumes p_reflection:
       
   775     "!!f g h. REFLECTS[\<lambda>x. p(L, f(x), g(x)), 
       
   776                      \<lambda>i x. p(**Lset(i), f(x), g(x))]"
       
   777  shows "REFLECTS[\<lambda>x. iterates_MH(L, p(L), e(x), f(x), g(x), h(x)), 
       
   778                \<lambda>i x. iterates_MH(**Lset(i), p(**Lset(i)), e(x), f(x), g(x), h(x))]"
       
   779 apply (simp (no_asm_use) only: iterates_MH_def)
       
   780 txt{*Must be careful: simplifying with @{text setclass_simps} above would
       
   781      change @{text "\<exists>gm[**Lset(i)]"} into @{text "\<exists>gm \<in> Lset(i)"}, when
       
   782      it would no longer match rule @{text is_nat_case_reflection}. *}
       
   783 apply (rule is_nat_case_reflection) 
       
   784 apply (simp (no_asm_use) only: setclass_simps)
       
   785 apply (intro FOL_reflections function_reflections is_nat_case_reflection
       
   786              restriction_reflection p_reflection)  
       
   787 done
       
   788 
       
   789 
       
   790 
       
   791 subsection{*@{term L} is Closed Under the Operator @{term list}*} 
       
   792 
       
   793 
       
   794 lemma list_replacement1_Reflects:
       
   795  "REFLECTS
       
   796    [\<lambda>x. \<exists>u[L]. u \<in> B \<and> (\<exists>y[L]. pair(L,u,y,x) \<and>
       
   797          is_wfrec(L, iterates_MH(L, is_list_functor(L,A), 0), memsn, u, y)),
       
   798     \<lambda>i x. \<exists>u \<in> Lset(i). u \<in> B \<and> (\<exists>y \<in> Lset(i). pair(**Lset(i), u, y, x) \<and>
       
   799          is_wfrec(**Lset(i), 
       
   800                   iterates_MH(**Lset(i), 
       
   801                           is_list_functor(**Lset(i), A), 0), memsn, u, y))]"
       
   802 by (intro FOL_reflections function_reflections is_wfrec_reflection 
       
   803           iterates_MH_reflection list_functor_reflection) 
       
   804 
       
   805 lemma list_replacement1: 
       
   806    "L(A) ==> iterates_replacement(L, is_list_functor(L,A), 0)"
       
   807 apply (unfold iterates_replacement_def wfrec_replacement_def, clarify)
       
   808 apply (rule strong_replacementI) 
       
   809 apply (rule rallI)
       
   810 apply (rename_tac B)   
       
   811 apply (rule separation_CollectI) 
       
   812 apply (insert nonempty) 
       
   813 apply (subgoal_tac "L(Memrel(succ(n)))") 
       
   814 apply (rule_tac A="{B,A,n,z,0,Memrel(succ(n))}" in subset_LsetE, blast ) 
       
   815 apply (rule ReflectsE [OF list_replacement1_Reflects], assumption)
       
   816 apply (drule subset_Lset_ltD, assumption) 
       
   817 apply (erule reflection_imp_L_separation)
       
   818   apply (simp_all add: lt_Ord2)
       
   819 apply (rule DPowI2)
       
   820 apply (rename_tac v) 
       
   821 apply (rule bex_iff_sats conj_iff_sats)+
       
   822 apply (rule_tac env = "[u,v,A,n,B,0,Memrel(succ(n))]" in mem_iff_sats)
       
   823 apply (rule sep_rules | simp)+
       
   824 txt{*Can't get sat rules to work for higher-order operators, so just expand them!*}
       
   825 apply (simp add: is_wfrec_def M_is_recfun_def iterates_MH_def is_nat_case_def)
       
   826 apply (rule sep_rules list_functor_iff_sats quasinat_iff_sats | simp)+
       
   827 apply (simp_all add: succ_Un_distrib [symmetric] Memrel_closed)
       
   828 done
       
   829 
       
   830 
       
   831 lemma list_replacement2_Reflects:
       
   832  "REFLECTS
       
   833    [\<lambda>x. \<exists>u[L]. u \<in> B \<and> u \<in> nat \<and>
       
   834          (\<exists>sn[L]. \<exists>msn[L]. successor(L, u, sn) \<and> membership(L, sn, msn) \<and>
       
   835            is_wfrec (L, iterates_MH (L, is_list_functor(L, A), 0),
       
   836                               msn, u, x)),
       
   837     \<lambda>i x. \<exists>u \<in> Lset(i). u \<in> B \<and> u \<in> nat \<and>
       
   838          (\<exists>sn \<in> Lset(i). \<exists>msn \<in> Lset(i). 
       
   839           successor(**Lset(i), u, sn) \<and> membership(**Lset(i), sn, msn) \<and>
       
   840            is_wfrec (**Lset(i), 
       
   841                  iterates_MH (**Lset(i), is_list_functor(**Lset(i), A), 0),
       
   842                      msn, u, x))]"
       
   843 by (intro FOL_reflections function_reflections is_wfrec_reflection 
       
   844           iterates_MH_reflection list_functor_reflection) 
       
   845 
       
   846 
       
   847 lemma list_replacement2: 
       
   848    "L(A) ==> strong_replacement(L, 
       
   849          \<lambda>n y. n\<in>nat & 
       
   850                (\<exists>sn[L]. \<exists>msn[L]. successor(L,n,sn) & membership(L,sn,msn) &
       
   851                is_wfrec(L, iterates_MH(L,is_list_functor(L,A), 0), 
       
   852                         msn, n, y)))"
       
   853 apply (rule strong_replacementI) 
       
   854 apply (rule rallI)
       
   855 apply (rename_tac B)   
       
   856 apply (rule separation_CollectI) 
       
   857 apply (insert nonempty) 
       
   858 apply (rule_tac A="{A,B,z,0,nat}" in subset_LsetE) 
       
   859 apply (blast intro: L_nat) 
       
   860 apply (rule ReflectsE [OF list_replacement2_Reflects], assumption)
       
   861 apply (drule subset_Lset_ltD, assumption) 
       
   862 apply (erule reflection_imp_L_separation)
       
   863   apply (simp_all add: lt_Ord2)
       
   864 apply (rule DPowI2)
       
   865 apply (rename_tac v) 
       
   866 apply (rule bex_iff_sats conj_iff_sats)+
       
   867 apply (rule_tac env = "[u,v,A,B,0,nat]" in mem_iff_sats)
       
   868 apply (rule sep_rules | simp)+
       
   869 apply (simp add: is_wfrec_def M_is_recfun_def iterates_MH_def is_nat_case_def)
       
   870 apply (rule sep_rules list_functor_iff_sats quasinat_iff_sats | simp)+
       
   871 apply (simp_all add: succ_Un_distrib [symmetric] Memrel_closed)
       
   872 done
       
   873 
       
   874 
       
   875 
   390 end
   876 end