src/ZF/AC/AC16_WO4.ML
changeset 12776 249600a63ba9
parent 12775 1748c16c2df3
child 12777 70b2651af635
equal deleted inserted replaced
12775:1748c16c2df3 12776:249600a63ba9
     1 (*  Title:      ZF/AC/AC16_WO4.ML
       
     2     ID:         $Id$
       
     3     Author:     Krzysztof Grabczewski
       
     4 
       
     5   The proof of AC16(n, k) ==> WO4(n-k)
       
     6 *)
       
     7 
       
     8 (* ********************************************************************** *)
       
     9 (* The case of finite set                                                 *)
       
    10 (* ********************************************************************** *)
       
    11 
       
    12 Goalw [Finite_def] "[| Finite(A); 0<m; m \\<in> nat |] ==>  \
       
    13 \       \\<exists>a f. Ord(a) & domain(f) = a &  \
       
    14 \               (\\<Union>b<a. f`b) = A & (\\<forall>b<a. f`b lepoll m)";
       
    15 by (etac bexE 1);
       
    16 by (dresolve_tac [eqpoll_sym RS (eqpoll_def RS def_imp_iff RS iffD1)] 1);
       
    17 by (etac exE 1);
       
    18 by (res_inst_tac [("x","n")] exI 1);
       
    19 by (res_inst_tac [("x","\\<lambda>i \\<in> n. {f`i}")] exI 1);
       
    20 by (Asm_full_simp_tac 1);
       
    21 by (rewrite_goals_tac [bij_def, surj_def]);
       
    22 by (fast_tac (claset() addSIs [ltI, nat_into_Ord, lam_funtype RS domain_of_fun,
       
    23         equalityI, singleton_eqpoll_1 RS eqpoll_imp_lepoll RS lepoll_trans,
       
    24         nat_1_lepoll_iff RS iffD2]
       
    25         addSEs [apply_type, ltE]) 1);
       
    26 val lemma1 = result();
       
    27 
       
    28 (* ********************************************************************** *)
       
    29 (* The case of infinite set                                               *)
       
    30 (* ********************************************************************** *)
       
    31 
       
    32 (* well_ord(x,r) ==> well_ord({{y,z}. y \\<in> x}, Something(x,z))  **)
       
    33 bind_thm ("well_ord_paired", (paired_bij RS bij_is_inj RS well_ord_rvimage));
       
    34 
       
    35 Goal "[| A lepoll B; ~ A lepoll C |] ==> ~ B lepoll C";
       
    36 by (fast_tac (claset() addEs [notE, lepoll_trans]) 1);
       
    37 qed "lepoll_trans1";
       
    38 
       
    39 (* ********************************************************************** *)
       
    40 (* There exists a well ordered set y such that ...                        *)
       
    41 (* ********************************************************************** *)
       
    42 
       
    43 val lepoll_paired = paired_eqpoll RS eqpoll_sym RS eqpoll_imp_lepoll;
       
    44 
       
    45 Goal "\\<exists>y R. well_ord(y,R) & x Int y = 0 & ~y lepoll z & ~Finite(y)";
       
    46 by (res_inst_tac [("x","{{a,x}. a \\<in> nat Un Hartog(z)}")] exI 1);
       
    47 by (resolve_tac [transfer thy Ord_nat RS well_ord_Memrel RS
       
    48 		 (Ord_Hartog RS
       
    49 		  well_ord_Memrel RSN (2, well_ord_Un)) RS exE] 1);
       
    50 by (fast_tac 
       
    51     (claset() addSIs [Ord_Hartog, well_ord_Memrel, well_ord_paired,
       
    52 		      HartogI RSN (2, lepoll_trans1),
       
    53 		 subset_imp_lepoll RS (lepoll_paired RSN (2, lepoll_trans))]
       
    54               addSEs [nat_not_Finite RS notE] addEs [mem_asym]
       
    55 	      addSDs [Un_upper1 RS subset_imp_lepoll RS lepoll_Finite,
       
    56 		      lepoll_paired RS lepoll_Finite]) 1);
       
    57 val lemma2 = result();
       
    58 
       
    59 Goal "~Finite(B) ==> ~Finite(A Un B)";
       
    60 by (blast_tac (claset() addIs [subset_Finite]) 1);
       
    61 qed "infinite_Un";
       
    62 
       
    63 (* ********************************************************************** *)
       
    64 (* There is a v \\<in> s(u) such that k lepoll x Int y (in our case succ(k))    *)
       
    65 (* The idea of the proof is the following \\<in>                               *)
       
    66 (* Suppose not, i.e. every element of s(u) has exactly k-1 elements of y   *)
       
    67 (* Thence y is less than or equipollent to {v \\<in> Pow(x). v eqpoll n#-k}      *)
       
    68 (*   We have obtained this result in two steps \\<in>                          *)
       
    69 (*   1. y is less than or equipollent to {v \\<in> s(u). a \\<subseteq> v}                  *)
       
    70 (*      where a is certain k-2 element subset of y                        *)
       
    71 (*   2. {v \\<in> s(u). a \\<subseteq> v} is less than or equipollent                       *)
       
    72 (*      to {v \\<in> Pow(x). v eqpoll n-k}                                       *)
       
    73 (* ********************************************************************** *)
       
    74 
       
    75 (*Proof simplified by LCP*)
       
    76 Goal "[| ~(\\<exists>x \\<in> A. f`x=y); f \\<in> inj(A, B); y \\<in> B |]  \
       
    77 \     ==> (\\<lambda>a \\<in> succ(A). if(a=A, y, f`a)) \\<in> inj(succ(A), B)";
       
    78 by (res_inst_tac [("d","%z. if(z=y, A, converse(f)`z)")] lam_injective 1);
       
    79 by (force_tac (claset(), simpset() addsimps [inj_is_fun RS apply_type]) 1);
       
    80 (*this preliminary simplification prevents looping somehow*)
       
    81 by (Asm_simp_tac 1);  
       
    82 by (force_tac (claset(), simpset() addsimps []) 1);  
       
    83 qed "succ_not_lepoll_lemma";
       
    84 
       
    85 Goalw [lepoll_def, eqpoll_def, bij_def, surj_def]
       
    86         "[| ~A eqpoll B; A lepoll B |] ==> succ(A) lepoll B";
       
    87 by (fast_tac (claset() addSEs [succ_not_lepoll_lemma, inj_is_fun]) 1);
       
    88 qed "succ_not_lepoll_imp_eqpoll";
       
    89 
       
    90 
       
    91 (* ********************************************************************** *)
       
    92 (* There is a k-2 element subset of y                                     *)
       
    93 (* ********************************************************************** *)
       
    94 
       
    95 val ordertype_eqpoll =
       
    96         ordermap_bij RS (exI RS (eqpoll_def RS def_imp_iff RS iffD2));
       
    97 
       
    98 Goal "[| a \\<subseteq> y; b \\<in> y-a; u \\<in> x |] ==> cons(b, cons(u, a)) \\<in> Pow(x Un y)";
       
    99 by (Fast_tac 1);
       
   100 qed "cons_cons_subset";
       
   101 
       
   102 Goal "[| a eqpoll k; a \\<subseteq> y; b \\<in> y-a; u \\<in> x; x Int y = 0 |]   \
       
   103 \     ==> cons(b, cons(u, a)) eqpoll succ(succ(k))";
       
   104 by (fast_tac (claset() addSIs [cons_eqpoll_succ]) 1);
       
   105 qed "cons_cons_eqpoll";
       
   106 
       
   107 Goal "[| succ(k) eqpoll A; k eqpoll B; B \\<subseteq> A; a \\<in> A-B; k \\<in> nat |]   \
       
   108 \     ==> A = cons(a, B)";
       
   109 by (rtac equalityI 1);
       
   110 by (Fast_tac 2);
       
   111 by (resolve_tac [Diff_eq_0_iff RS iffD1] 1);
       
   112 by (rtac equals0I 1);
       
   113 by (dresolve_tac [eqpoll_sym RS eqpoll_imp_lepoll] 1);
       
   114 by (dresolve_tac [eqpoll_sym RS cons_eqpoll_succ] 1);
       
   115 by (Fast_tac 1);
       
   116 by (dtac cons_eqpoll_succ 1);
       
   117 by (Fast_tac 1);
       
   118 by (fast_tac 
       
   119     (claset() 
       
   120         addSEs [[eqpoll_sym RS eqpoll_imp_lepoll, subset_imp_lepoll] MRS
       
   121         (lepoll_trans RS lepoll_trans) RS succ_lepoll_natE]) 1);
       
   122 qed "set_eq_cons";
       
   123 
       
   124 Goal "[| cons(x,a) = cons(y,a); x\\<notin> a |] ==> x = y ";
       
   125 by (fast_tac (claset() addSEs [equalityE]) 1);
       
   126 qed "cons_eqE";
       
   127 
       
   128 Goal "A = B ==> A Int C = B Int C";
       
   129 by (Asm_simp_tac 1);
       
   130 qed "eq_imp_Int_eq";
       
   131 
       
   132 (* ********************************************************************** *)
       
   133 (* some arithmetic                                                        *)
       
   134 (* ********************************************************************** *)
       
   135 
       
   136 Goal "[| k \\<in> nat; m \\<in> nat |] ==>  \
       
   137 \       \\<forall>A B. A eqpoll k #+ m & k lepoll B & B \\<subseteq> A --> A-B lepoll m";
       
   138 by (induct_tac "k" 1);
       
   139 by (asm_simp_tac (simpset() addsimps [add_0]) 1);
       
   140 by (fast_tac (claset() addIs [eqpoll_imp_lepoll RS
       
   141         (Diff_subset RS subset_imp_lepoll RS lepoll_trans)]) 1);
       
   142 by (REPEAT (resolve_tac [allI,impI] 1));
       
   143 by (resolve_tac [succ_lepoll_imp_not_empty RS not_emptyE] 1);
       
   144 by (Fast_tac 1);
       
   145 by (eres_inst_tac [("x","A - {xa}")] allE 1);
       
   146 by (eres_inst_tac [("x","B - {xa}")] allE 1);
       
   147 by (etac impE 1);
       
   148 by (asm_full_simp_tac (simpset() addsimps [add_succ]) 1);
       
   149 by (fast_tac (claset() addSIs [Diff_sing_eqpoll, lepoll_Diff_sing]) 1);
       
   150 by (res_inst_tac [("P","%z. z lepoll m")] subst 1 THEN (assume_tac 2));
       
   151 by (Fast_tac 1);
       
   152 qed "eqpoll_sum_imp_Diff_lepoll_lemma";
       
   153 
       
   154 Goal "[| A eqpoll succ(k #+ m); B \\<subseteq> A; succ(k) lepoll B;  k \\<in> nat; m \\<in> nat |]  \
       
   155 \     ==> A-B lepoll m";
       
   156 by (dresolve_tac [add_succ RS ssubst] 1);
       
   157 by (dresolve_tac [nat_succI RS eqpoll_sum_imp_Diff_lepoll_lemma] 1
       
   158         THEN (REPEAT (assume_tac 1)));
       
   159 by (Fast_tac 1);
       
   160 qed "eqpoll_sum_imp_Diff_lepoll";
       
   161 
       
   162 (* ********************************************************************** *)
       
   163 (* similar properties for eqpoll                                          *)
       
   164 (* ********************************************************************** *)
       
   165 
       
   166 Goal "[| k \\<in> nat; m \\<in> nat |] ==>  \
       
   167 \       \\<forall>A B. A eqpoll k #+ m & k eqpoll B & B \\<subseteq> A --> A-B eqpoll m";
       
   168 by (induct_tac "k" 1);
       
   169 by (fast_tac (claset() addSDs [eqpoll_sym RS eqpoll_imp_lepoll RS lepoll_0_is_0]
       
   170         addss (simpset() addsimps [add_0])) 1);
       
   171 by (REPEAT (resolve_tac [allI,impI] 1));
       
   172 by (resolve_tac [succ_lepoll_imp_not_empty RS not_emptyE] 1);
       
   173 by (fast_tac (claset() addSEs [eqpoll_imp_lepoll]) 1);
       
   174 by (eres_inst_tac [("x","A - {xa}")] allE 1);
       
   175 by (eres_inst_tac [("x","B - {xa}")] allE 1);
       
   176 by (etac impE 1);
       
   177 by (fast_tac (claset() addSIs [Diff_sing_eqpoll,
       
   178         eqpoll_sym RSN (2, Diff_sing_eqpoll) RS eqpoll_sym]
       
   179         addss (simpset() addsimps [add_succ])) 1);
       
   180 by (res_inst_tac [("P","%z. z eqpoll m")] subst 1 THEN (assume_tac 2));
       
   181 by (Fast_tac 1);
       
   182 qed "eqpoll_sum_imp_Diff_eqpoll_lemma";
       
   183 
       
   184 Goal "[| A eqpoll succ(k #+ m); B \\<subseteq> A; succ(k) eqpoll B; k \\<in> nat; m \\<in> nat |]  \
       
   185 \     ==> A-B eqpoll m";
       
   186 by (dresolve_tac [add_succ RS ssubst] 1);
       
   187 by (dresolve_tac [nat_succI RS eqpoll_sum_imp_Diff_eqpoll_lemma] 1
       
   188         THEN (REPEAT (assume_tac 1)));
       
   189 by (Fast_tac 1);
       
   190 qed "eqpoll_sum_imp_Diff_eqpoll";
       
   191 
       
   192 
       
   193 (* ********************************************************************** *)
       
   194 (* LL can be well ordered                                                 *)
       
   195 (* ********************************************************************** *)
       
   196 
       
   197 Goal "{x \\<in> Pow(X). x lepoll 0} = {0}";
       
   198 by (fast_tac (claset() addSDs [lepoll_0_is_0] addSIs [lepoll_refl]) 1);
       
   199 qed "subsets_lepoll_0_eq_unit";
       
   200 
       
   201 Goal "n \\<in> nat ==> {z \\<in> Pow(y). z lepoll succ(n)} =  \
       
   202 \               {z \\<in> Pow(y). z lepoll n} Un {z \\<in> Pow(y). z eqpoll succ(n)}";
       
   203 by (fast_tac (claset() addIs [le_refl, leI, le_imp_lepoll]
       
   204                 addSDs [lepoll_succ_disj]
       
   205                 addSEs [nat_into_Ord, lepoll_trans, eqpoll_imp_lepoll]) 1);
       
   206 qed "subsets_lepoll_succ";
       
   207 
       
   208 Goal "n \\<in> nat ==> {z \\<in> Pow(y). z lepoll n} Int {z \\<in> Pow(y). z eqpoll succ(n)} = 0";
       
   209 by (fast_tac (claset() addSEs [eqpoll_sym RS eqpoll_imp_lepoll 
       
   210                 RS lepoll_trans RS succ_lepoll_natE]
       
   211                 addSIs [equals0I]) 1);
       
   212 qed "Int_empty";
       
   213 
       
   214 
       
   215 Open_locale "AC16"; 
       
   216 
       
   217 val all_ex = thm "all_ex";
       
   218 val disjoint = thm "disjoint";
       
   219 val includes = thm "includes";
       
   220 val WO_R = thm "WO_R";
       
   221 val k_def = thm "k_def";
       
   222 val lnat = thm "lnat";
       
   223 val mnat = thm "mnat";
       
   224 val mpos = thm "mpos";
       
   225 val Infinite = thm "Infinite";
       
   226 val noLepoll = thm "noLepoll";
       
   227 
       
   228 val LL_def = thm "LL_def";
       
   229 val MM_def = thm "MM_def";
       
   230 val GG_def = thm "GG_def";
       
   231 val s_def = thm "s_def";
       
   232 
       
   233 Addsimps [disjoint, WO_R, lnat, mnat, mpos, Infinite];
       
   234 AddSIs [disjoint, WO_R, lnat, mnat, mpos];
       
   235 
       
   236 Goalw [k_def] "k \\<in> nat";
       
   237 by Auto_tac;
       
   238 qed "knat";
       
   239 Addsimps [knat];  AddSIs [knat];
       
   240 
       
   241 AddSIs [Infinite];   (*if notI is removed!*)
       
   242 AddSEs [Infinite RS notE];
       
   243 
       
   244 AddEs [[disjoint, IntI] MRS (equals0D RS notE)];
       
   245 
       
   246 (*use k = succ(l) *)
       
   247 val includes_l = simplify (FOL_ss addsimps [k_def]) includes;
       
   248 val all_ex_l = simplify (FOL_ss addsimps [k_def]) all_ex;
       
   249 
       
   250 (* ********************************************************************** *)
       
   251 (*   1. y is less than or equipollent to {v \\<in> s(u). a \\<subseteq> v}                  *)
       
   252 (*      where a is certain k-2 element subset of y                        *)
       
   253 (* ********************************************************************** *)
       
   254 
       
   255 Goal "[| l eqpoll a; a \\<subseteq> y |] ==> y - a eqpoll y";
       
   256 by (cut_facts_tac [WO_R, Infinite, lnat] 1);
       
   257 by (fast_tac (empty_cs addIs [lesspoll_trans1]
       
   258         addSIs [Card_cardinal, Diff_lesspoll_eqpoll_Card RS eqpoll_trans,
       
   259                 Card_cardinal RS Card_is_Ord RS nat_le_infinite_Ord
       
   260                 RS le_imp_lepoll]
       
   261         addSEs [well_ord_cardinal_eqpoll,
       
   262                 well_ord_cardinal_eqpoll RS eqpoll_sym,
       
   263                 eqpoll_sym RS eqpoll_imp_lepoll,
       
   264                 n_lesspoll_nat RS lesspoll_trans2,
       
   265                 well_ord_cardinal_eqpoll RS eqpoll_sym RS eqpoll_imp_lepoll
       
   266                 RS lepoll_infinite]) 1);
       
   267 qed "Diff_Finite_eqpoll";
       
   268 
       
   269 Goalw [s_def] "s(u) \\<subseteq> t_n";
       
   270 by (Fast_tac 1);
       
   271 qed "s_subset";
       
   272 
       
   273 Goalw [s_def, succ_def, k_def]
       
   274       "[| w \\<in> t_n; cons(b,cons(u,a)) \\<subseteq> w; a \\<subseteq> y; b \\<in> y-a; l eqpoll a  \
       
   275 \      |] ==> w \\<in> s(u)";
       
   276 by (fast_tac (claset() addDs [eqpoll_imp_lepoll RS cons_lepoll_cong]
       
   277                 addSEs [subset_imp_lepoll RSN (2, lepoll_trans)]) 1);
       
   278 qed "sI";
       
   279 
       
   280 Goalw [s_def] "v \\<in> s(u) ==> u \\<in> v";
       
   281 by (Fast_tac 1);
       
   282 qed "in_s_imp_u_in";
       
   283 
       
   284 
       
   285 Goal "[| l eqpoll a;  a \\<subseteq> y;  b \\<in> y - a;  u \\<in> x |]  \
       
   286 \     ==> \\<exists>! c. c \\<in> s(u) & a \\<subseteq> c & b \\<in> c";
       
   287 by (rtac (all_ex_l RS ballE) 1);
       
   288 by (blast_tac (claset() delrules [PowI]
       
   289 		        addSIs [cons_cons_subset,
       
   290 				eqpoll_sym RS cons_cons_eqpoll]) 2);
       
   291 by (etac ex1E 1);
       
   292 by (res_inst_tac [("a","w")] ex1I 1);
       
   293 by (blast_tac (claset() addIs [sI]) 1);
       
   294 by (etac allE 1);
       
   295 by (etac impE 1);
       
   296 by (assume_tac 2);
       
   297 by (fast_tac (claset() addSEs [s_subset RS subsetD, in_s_imp_u_in]) 1);
       
   298 qed "ex1_superset_a";
       
   299 
       
   300 Goal "[| \\<forall>v \\<in> s(u). succ(l) eqpoll v Int y;  \
       
   301 \        l eqpoll a;  a \\<subseteq> y;  b \\<in> y - a;  u \\<in> x |]   \
       
   302 \     ==> (THE c. c \\<in> s(u) & a \\<subseteq> c & b \\<in> c)  \
       
   303 \              Int y = cons(b, a)";
       
   304 by (forward_tac [ex1_superset_a RS theI] 1 THEN REPEAT (assume_tac 1));
       
   305 by (rtac set_eq_cons 1);
       
   306 by (REPEAT (Fast_tac 1));
       
   307 qed "the_eq_cons";
       
   308 
       
   309 Goal "[| \\<forall>v \\<in> s(u). succ(l) eqpoll v Int y;  \
       
   310 \        l eqpoll a;  a \\<subseteq> y;  u \\<in> x |]  \
       
   311 \     ==> y lepoll {v \\<in> s(u). a \\<subseteq> v}";
       
   312 by (resolve_tac [Diff_Finite_eqpoll RS eqpoll_sym RS 
       
   313 		 eqpoll_imp_lepoll RS lepoll_trans] 1
       
   314     THEN REPEAT (Fast_tac 1));
       
   315 by (res_inst_tac 
       
   316      [("f3", "\\<lambda>b \\<in> y-a. THE c. c \\<in> s(u) & a \\<subseteq> c & b \\<in> c")]
       
   317      (exI RS (lepoll_def RS def_imp_iff RS iffD2)) 1);
       
   318 by (simp_tac (simpset() addsimps [inj_def]) 1);
       
   319 by (rtac conjI 1);
       
   320 by (rtac lam_type 1);
       
   321 by (forward_tac [ex1_superset_a RS theI] 1 THEN REPEAT (Fast_tac 1));
       
   322 by (Asm_simp_tac 1);
       
   323 by (Clarify_tac 1);
       
   324 by (rtac cons_eqE 1);
       
   325 by (Fast_tac 2);
       
   326 by (dres_inst_tac [("A","THE c. ?P(c)"), ("C","y")] eq_imp_Int_eq 1);
       
   327 by (asm_full_simp_tac (simpset() addsimps [the_eq_cons]) 1);
       
   328 qed "y_lepoll_subset_s";
       
   329 
       
   330 
       
   331 (* ********************************************************************** *)
       
   332 (* back to the second part                                                *)
       
   333 (* ********************************************************************** *)
       
   334 
       
   335 Goal "w \\<subseteq> x Un y ==> w Int (x - {u}) = w - cons(u, w Int y)";
       
   336 by (Fast_tac 1);
       
   337 qed "w_Int_eq_w_Diff";
       
   338 
       
   339 Goal "[| w \\<in> {v \\<in> s(u). a \\<subseteq> v};  \
       
   340 \        l eqpoll a;  u \\<in> x;  \
       
   341 \        \\<forall>v \\<in> s(u). succ(l) eqpoll v Int y  \
       
   342 \     |] ==> w Int (x - {u}) eqpoll m";
       
   343 by (etac CollectE 1);
       
   344 by (stac w_Int_eq_w_Diff 1);
       
   345 by (fast_tac (claset() addSDs [s_subset RS subsetD,
       
   346 			       includes_l RS subsetD]) 1);
       
   347 by (fast_tac (claset() addSDs [bspec]
       
   348         addDs [s_subset RS subsetD, includes_l RS subsetD]
       
   349         addSEs [eqpoll_sym RS cons_eqpoll_succ RS eqpoll_sym, in_s_imp_u_in]
       
   350         addSIs [eqpoll_sum_imp_Diff_eqpoll]) 1);
       
   351 qed "w_Int_eqpoll_m";
       
   352 
       
   353 (* ********************************************************************** *)
       
   354 (*   2. {v \\<in> s(u). a \\<subseteq> v} is less than or equipollent                       *)
       
   355 (*      to {v \\<in> Pow(x). v eqpoll n-k}                                       *)
       
   356 (* ********************************************************************** *)
       
   357 
       
   358 Goal "x eqpoll m ==> x \\<noteq> 0";
       
   359 by (cut_facts_tac [mpos] 1);
       
   360 by (fast_tac (claset() addSEs [zero_lt_natE]
       
   361 		       addSDs [eqpoll_succ_imp_not_empty]) 1);
       
   362 qed "eqpoll_m_not_empty";
       
   363 
       
   364 Goal "[| z \\<in> xa Int (x - {u}); l eqpoll a; a \\<subseteq> y; u \\<in> x |]  \
       
   365 \     ==> \\<exists>! w. w \\<in> t_n & cons(z, cons(u, a)) \\<subseteq> w";
       
   366 by (rtac (all_ex RS bspec) 1);
       
   367 by (rewtac k_def);
       
   368 by (fast_tac (claset() addSIs [cons_eqpoll_succ] addEs [eqpoll_sym]) 1);
       
   369 qed "cons_cons_in";
       
   370 
       
   371 Goal "[| \\<forall>v \\<in> s(u). succ(l) eqpoll v Int y;  \
       
   372 \        a \\<subseteq> y; l eqpoll a; u \\<in> x |]  \
       
   373 \     ==> {v \\<in> s(u). a \\<subseteq> v} lepoll {v \\<in> Pow(x). v eqpoll m}";
       
   374 by (res_inst_tac [("f3","\\<lambda>w \\<in> {v \\<in> s(u). a \\<subseteq> v}. w Int (x - {u})")] 
       
   375         (exI RS (lepoll_def RS def_imp_iff RS iffD2)) 1);
       
   376 by (simp_tac (simpset() addsimps [inj_def]) 1);
       
   377 by (rtac conjI 1);
       
   378 by (rtac lam_type 1);
       
   379 by (rtac CollectI 1);
       
   380 by (Fast_tac 1);
       
   381 by (rtac w_Int_eqpoll_m 1 THEN REPEAT (assume_tac 1));
       
   382 by (REPEAT (resolve_tac [ballI, impI] 1));
       
   383 (** LEVEL 8 **)
       
   384 by (resolve_tac [w_Int_eqpoll_m RS eqpoll_m_not_empty RS not_emptyE] 1);
       
   385 by (EVERY (map Blast_tac [4,3,2,1]));
       
   386 by (dresolve_tac [equalityD1 RS subsetD] 1 THEN (assume_tac 1));
       
   387 by (ftac cons_cons_in 1 THEN REPEAT (assume_tac 1));
       
   388 by (etac ex1_two_eq 1);
       
   389 by (REPEAT (blast_tac
       
   390 	    (claset() addDs [s_subset RS subsetD, in_s_imp_u_in]) 1));
       
   391 qed "subset_s_lepoll_w";
       
   392 
       
   393 
       
   394 (* ********************************************************************** *)
       
   395 (* well_ord_subsets_lepoll_n                                              *)
       
   396 (* ********************************************************************** *)
       
   397 
       
   398 Goal "n \\<in> nat ==> \\<exists>S. well_ord({z \\<in> Pow(y) . z eqpoll succ(n)}, S)";
       
   399 by (resolve_tac [WO_R RS well_ord_infinite_subsets_eqpoll_X
       
   400 		 RS (eqpoll_def RS def_imp_iff RS iffD1) RS exE] 1);
       
   401 by (REPEAT (fast_tac (claset() addIs [bij_is_inj RS well_ord_rvimage]) 1));
       
   402 qed "well_ord_subsets_eqpoll_n";
       
   403 
       
   404 Goal "n \\<in> nat ==> \\<exists>R. well_ord({z \\<in> Pow(y). z lepoll n}, R)";
       
   405 by (induct_tac "n" 1);
       
   406 by (force_tac (claset() addSIs [well_ord_unit],
       
   407 	       simpset() addsimps [subsets_lepoll_0_eq_unit]) 1);
       
   408 by (etac exE 1);
       
   409 by (resolve_tac [well_ord_subsets_eqpoll_n RS exE] 1 THEN assume_tac 1);
       
   410 by (asm_simp_tac (simpset() addsimps [subsets_lepoll_succ]) 1);
       
   411 by (dtac well_ord_radd 1 THEN (assume_tac 1));
       
   412 by (eresolve_tac [Int_empty RS disj_Un_eqpoll_sum RS 
       
   413                 (eqpoll_def RS def_imp_iff RS iffD1) RS exE] 1);
       
   414 by (fast_tac (claset() addSEs [bij_is_inj RS well_ord_rvimage]) 1);
       
   415 qed "well_ord_subsets_lepoll_n";
       
   416 
       
   417 
       
   418 Goalw [LL_def, MM_def] "LL \\<subseteq> {z \\<in> Pow(y). z lepoll succ(k #+ m)}";
       
   419 by (cut_facts_tac [includes] 1);
       
   420 by (fast_tac (claset() addIs [subset_imp_lepoll 
       
   421 			      RS (eqpoll_imp_lepoll
       
   422 				  RSN (2, lepoll_trans))]) 1);
       
   423 qed "LL_subset";
       
   424 
       
   425 Goal "\\<exists>S. well_ord(LL,S)";
       
   426 by (rtac (well_ord_subsets_lepoll_n RS exE) 1);
       
   427 by (blast_tac (claset() addIs [LL_subset RSN (2, well_ord_subset)]) 2);
       
   428 by Auto_tac;
       
   429 qed "well_ord_LL";
       
   430 
       
   431 (* ********************************************************************** *)
       
   432 (* every element of LL is a contained in exactly one element of MM        *)
       
   433 (* ********************************************************************** *)
       
   434 
       
   435 Goalw [MM_def, LL_def] "v \\<in> LL ==> \\<exists>! w. w \\<in> MM & v \\<subseteq> w";
       
   436 by Safe_tac;
       
   437 by (Fast_tac 1);
       
   438 by (resolve_tac [lepoll_imp_eqpoll_subset RS exE] 1 THEN (assume_tac 1));
       
   439 by (res_inst_tac [("x","x")] (all_ex RS ballE) 1);
       
   440 by (fast_tac (claset() addSEs [eqpoll_sym]) 2);
       
   441 by (Blast_tac 1);
       
   442 qed "unique_superset_in_MM";
       
   443 
       
   444 val unique_superset1 = unique_superset_in_MM RS theI RS conjunct1;
       
   445 val unique_superset2 = unique_superset_in_MM RS the_equality2;
       
   446 
       
   447 
       
   448 (* ********************************************************************** *)
       
   449 (* The function GG satisfies the conditions of WO4                        *)
       
   450 (* ********************************************************************** *)
       
   451 
       
   452 (* ********************************************************************** *)
       
   453 (* The union of appropriate values is the whole x                         *)
       
   454 (* ********************************************************************** *)
       
   455 
       
   456 Goalw [LL_def] "w \\<in> MM ==> w Int y \\<in> LL";
       
   457 by (Fast_tac 1);
       
   458 qed "Int_in_LL";
       
   459 
       
   460 Goalw [LL_def] 
       
   461      "v \\<in> LL ==> v = (THE x. x \\<in> MM & v \\<subseteq> x) Int y";
       
   462 by (Clarify_tac 1);
       
   463 by (stac unique_superset2 1);
       
   464 by (auto_tac (claset(), simpset() addsimps [Int_in_LL]));
       
   465 qed "in_LL_eq_Int";
       
   466 
       
   467 Goal "v \\<in> LL ==> (THE x. x \\<in> MM & v \\<subseteq> x) \\<subseteq> x Un y";
       
   468 by (dtac unique_superset1 1);
       
   469 by (rewtac MM_def);
       
   470 by (fast_tac (claset() addSDs [unique_superset1, includes RS subsetD]) 1);
       
   471 qed "the_in_MM_subset";
       
   472 
       
   473 Goalw [GG_def] "v \\<in> LL ==> GG ` v \\<subseteq> x";
       
   474 by (ftac the_in_MM_subset 1);
       
   475 by (ftac in_LL_eq_Int 1); 
       
   476 by (force_tac (claset() addEs [equalityE], simpset()) 1);
       
   477 qed "GG_subset";
       
   478 
       
   479 
       
   480 Goal "n \\<in> nat ==> \\<exists>z. z \\<subseteq> y & n eqpoll z";
       
   481 by (etac nat_lepoll_imp_ex_eqpoll_n 1);
       
   482 by (resolve_tac [ordertype_eqpoll RS eqpoll_sym RS eqpoll_imp_lepoll
       
   483         RSN (2, lepoll_trans)] 1);
       
   484 by (rtac WO_R 2);
       
   485 by (fast_tac 
       
   486     (claset() delrules [notI]
       
   487               addSIs [nat_le_infinite_Ord RS le_imp_lepoll]
       
   488 	      addIs [Ord_ordertype, 
       
   489 		     ordertype_eqpoll RS eqpoll_imp_lepoll
       
   490 		     RS lepoll_infinite]) 1);
       
   491 qed "ex_subset_eqpoll_n";
       
   492 
       
   493 
       
   494 Goal "u \\<in> x ==> \\<exists>v \\<in> s(u). succ(k) lepoll v Int y";
       
   495 by (rtac ccontr 1);
       
   496 by (subgoal_tac "\\<forall>v \\<in> s(u). k eqpoll v Int y" 1);
       
   497 by (full_simp_tac (simpset() addsimps [s_def]) 2);
       
   498 by (blast_tac (claset() addIs [succ_not_lepoll_imp_eqpoll]) 2);
       
   499 by (rewtac k_def);
       
   500 by (cut_facts_tac [all_ex, includes, lnat] 1);
       
   501 by (rtac (ex_subset_eqpoll_n RS exE) 1 THEN assume_tac 1);
       
   502 by (rtac (noLepoll RS notE) 1);
       
   503 by (blast_tac (claset() addIs
       
   504 	   [[y_lepoll_subset_s, subset_s_lepoll_w] MRS lepoll_trans]) 1);
       
   505 qed "exists_proper_in_s";
       
   506 
       
   507 Goal "u \\<in> x ==> \\<exists>w \\<in> MM. u \\<in> w";
       
   508 by (eresolve_tac [exists_proper_in_s RS bexE] 1);
       
   509 by (rewrite_goals_tac [MM_def, s_def]);
       
   510 by (Fast_tac 1);
       
   511 qed "exists_in_MM";
       
   512 
       
   513 Goal "u \\<in> x ==> \\<exists>w \\<in> LL. u \\<in> GG`w";
       
   514 by (rtac (exists_in_MM RS bexE) 1);
       
   515 by (assume_tac 1);
       
   516 by (rtac bexI 1);
       
   517 by (etac Int_in_LL 2);
       
   518 by (rewtac GG_def);
       
   519 by (asm_simp_tac (simpset() addsimps [Int_in_LL]) 1);
       
   520 by (stac unique_superset2 1);
       
   521 by (REPEAT (fast_tac (claset() addSEs [Int_in_LL]) 1));
       
   522 qed "exists_in_LL";
       
   523 
       
   524 
       
   525 Goal "well_ord(LL,S) ==>      \
       
   526 \     (\\<Union>b<ordertype(LL,S). GG ` (converse(ordermap(LL,S)) ` b)) = x";
       
   527 by (rtac equalityI 1);
       
   528 by (rtac subsetI 1);
       
   529 by (etac OUN_E 1);
       
   530 by (resolve_tac [GG_subset RS subsetD] 1);
       
   531 by (assume_tac 2);
       
   532 by (blast_tac (claset() addIs [ordermap_bij RS bij_converse_bij RS
       
   533 			       bij_is_fun RS apply_type, ltD]) 1);
       
   534 by (rtac subsetI 1);
       
   535 by (eresolve_tac [exists_in_LL RS bexE] 1);
       
   536 by (force_tac (claset() addIs [Ord_ordertype RSN (2, ltI),
       
   537 			       ordermap_type RS apply_type],
       
   538         simpset() addsimps [ordermap_bij RS bij_is_inj RS left_inverse]) 1);
       
   539 qed "OUN_eq_x";
       
   540 
       
   541 (* ********************************************************************** *)
       
   542 (* Every element of the family is less than or equipollent to n-k (m)     *)
       
   543 (* ********************************************************************** *)
       
   544 
       
   545 Goalw [MM_def] "w \\<in> MM ==> w eqpoll succ(k #+ m)";
       
   546 by (fast_tac (claset() addDs [includes RS subsetD]) 1);
       
   547 qed "in_MM_eqpoll_n";
       
   548 
       
   549 Goalw [LL_def, MM_def] "w \\<in> LL ==> succ(k) lepoll w";
       
   550 by (Fast_tac 1);
       
   551 qed "in_LL_eqpoll_n";
       
   552 
       
   553 val in_LL = in_LL_eq_Int RS equalityD1 RS (Int_lower1 RSN (2, subset_trans));
       
   554 
       
   555 Goalw [GG_def] 
       
   556       "well_ord(LL,S) ==>      \
       
   557 \      \\<forall>b<ordertype(LL,S). GG ` (converse(ordermap(LL,S)) ` b) lepoll m";
       
   558 by (rtac oallI 1);
       
   559 by (asm_simp_tac 
       
   560     (simpset() addsimps [ltD,
       
   561 			 ordermap_bij RS bij_converse_bij RS
       
   562 			 bij_is_fun RS apply_type]) 1);
       
   563 by (cut_facts_tac [includes] 1);
       
   564 by (rtac eqpoll_sum_imp_Diff_lepoll 1);
       
   565 by (REPEAT
       
   566     (fast_tac (claset() delrules [subsetI]
       
   567 		        addSDs [ltD]
       
   568 			addSIs [eqpoll_sum_imp_Diff_lepoll, in_LL_eqpoll_n]
       
   569 			addIs [unique_superset1 RS in_MM_eqpoll_n, in_LL,
       
   570 			       ordermap_bij RS bij_converse_bij RS 
       
   571 			       bij_is_fun RS apply_type]) 1 ));
       
   572 qed "all_in_lepoll_m";
       
   573 
       
   574 
       
   575 Goal "\\<exists>a f. Ord(a) & domain(f) = a &  \
       
   576 \             (\\<Union>b<a. f ` b) = x & (\\<forall>b<a. f ` b lepoll m)";
       
   577 by (resolve_tac [well_ord_LL RS exE] 1 THEN REPEAT (assume_tac 1));
       
   578 by (rename_tac "S" 1);
       
   579 by (res_inst_tac [("x","ordertype(LL,S)")] exI 1);
       
   580 by (res_inst_tac [("x",
       
   581         "\\<lambda>b \\<in> ordertype(LL,S). GG ` (converse(ordermap(LL,S)) ` b)")] 
       
   582     exI 1);
       
   583 by (Simp_tac 1);
       
   584 by (REPEAT (ares_tac [conjI, lam_funtype RS domain_of_fun,
       
   585 		      Ord_ordertype, 
       
   586 		      all_in_lepoll_m, OUN_eq_x] 1));
       
   587 qed "conclusion";
       
   588 
       
   589 Close_locale "AC16";
       
   590 
       
   591 
       
   592 
       
   593 (* ********************************************************************** *)
       
   594 (* The main theorem AC16(n, k) ==> WO4(n-k)                               *)
       
   595 (* ********************************************************************** *)
       
   596 
       
   597 Goalw [AC16_def,WO4_def]
       
   598         "[| AC16(k #+ m, k); 0 < k; 0 < m; k \\<in> nat; m \\<in> nat |] ==> WO4(m)";
       
   599 by (rtac allI 1);
       
   600 by (case_tac "Finite(A)" 1);
       
   601 by (rtac lemma1 1 THEN REPEAT (assume_tac 1));
       
   602 by (cut_facts_tac [lemma2] 1);
       
   603 by (REPEAT (eresolve_tac [exE, conjE] 1));
       
   604 by (eres_inst_tac [("x","A Un y")] allE 1);
       
   605 by (ftac infinite_Un 1 THEN (mp_tac 1));
       
   606 by (etac zero_lt_natE 1); 
       
   607 by (assume_tac 1);
       
   608 by (Clarify_tac 1);
       
   609 by (DEPTH_SOLVE (ares_tac [export conclusion] 1));
       
   610 qed "AC16_WO4";
       
   611