src/ZF/Constructible/Wellorderings.thy
author paulson
Fri Oct 04 15:57:32 2002 +0200 (2002-10-04)
changeset 13628 87482b5e3f2e
parent 13615 449a70d88b38
child 13634 99a593b49b04
permissions -rw-r--r--
Various simplifications of the Constructible theories
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(*  Title:      ZF/Constructible/Wellorderings.thy
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   2002  University of Cambridge
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*)
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header {*Relativized Wellorderings*}
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theory Wellorderings = Relative:
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text{*We define functions analogous to @{term ordermap} @{term ordertype} 
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      but without using recursion.  Instead, there is a direct appeal
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      to Replacement.  This will be the basis for a version relativized
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      to some class @{text M}.  The main result is Theorem I 7.6 in Kunen,
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      page 17.*}
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subsection{*Wellorderings*}
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constdefs
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  irreflexive :: "[i=>o,i,i]=>o"
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    "irreflexive(M,A,r) == \<forall>x[M]. x\<in>A --> <x,x> \<notin> r"
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  transitive_rel :: "[i=>o,i,i]=>o"
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    "transitive_rel(M,A,r) == 
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	\<forall>x[M]. x\<in>A --> (\<forall>y[M]. y\<in>A --> (\<forall>z[M]. z\<in>A --> 
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                          <x,y>\<in>r --> <y,z>\<in>r --> <x,z>\<in>r))"
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  linear_rel :: "[i=>o,i,i]=>o"
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    "linear_rel(M,A,r) == 
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	\<forall>x[M]. x\<in>A --> (\<forall>y[M]. y\<in>A --> <x,y>\<in>r | x=y | <y,x>\<in>r)"
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  wellfounded :: "[i=>o,i]=>o"
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    --{*EVERY non-empty set has an @{text r}-minimal element*}
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    "wellfounded(M,r) == 
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	\<forall>x[M]. x\<noteq>0 --> (\<exists>y[M]. y\<in>x & ~(\<exists>z[M]. z\<in>x & <z,y> \<in> r))"
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  wellfounded_on :: "[i=>o,i,i]=>o"
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    --{*every non-empty SUBSET OF @{text A} has an @{text r}-minimal element*}
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    "wellfounded_on(M,A,r) == 
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	\<forall>x[M]. x\<noteq>0 --> x\<subseteq>A --> (\<exists>y[M]. y\<in>x & ~(\<exists>z[M]. z\<in>x & <z,y> \<in> r))"
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  wellordered :: "[i=>o,i,i]=>o"
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    --{*linear and wellfounded on @{text A}*}
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    "wellordered(M,A,r) == 
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	transitive_rel(M,A,r) & linear_rel(M,A,r) & wellfounded_on(M,A,r)"
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subsubsection {*Trivial absoluteness proofs*}
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lemma (in M_basic) irreflexive_abs [simp]: 
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     "M(A) ==> irreflexive(M,A,r) <-> irrefl(A,r)"
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by (simp add: irreflexive_def irrefl_def)
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lemma (in M_basic) transitive_rel_abs [simp]: 
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     "M(A) ==> transitive_rel(M,A,r) <-> trans[A](r)"
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by (simp add: transitive_rel_def trans_on_def)
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lemma (in M_basic) linear_rel_abs [simp]: 
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     "M(A) ==> linear_rel(M,A,r) <-> linear(A,r)"
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by (simp add: linear_rel_def linear_def)
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lemma (in M_basic) wellordered_is_trans_on: 
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    "[| wellordered(M,A,r); M(A) |] ==> trans[A](r)"
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by (auto simp add: wellordered_def)
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lemma (in M_basic) wellordered_is_linear: 
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    "[| wellordered(M,A,r); M(A) |] ==> linear(A,r)"
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by (auto simp add: wellordered_def)
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lemma (in M_basic) wellordered_is_wellfounded_on: 
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    "[| wellordered(M,A,r); M(A) |] ==> wellfounded_on(M,A,r)"
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by (auto simp add: wellordered_def)
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lemma (in M_basic) wellfounded_imp_wellfounded_on: 
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    "[| wellfounded(M,r); M(A) |] ==> wellfounded_on(M,A,r)"
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by (auto simp add: wellfounded_def wellfounded_on_def)
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lemma (in M_basic) wellfounded_on_subset_A:
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     "[| wellfounded_on(M,A,r);  B<=A |] ==> wellfounded_on(M,B,r)"
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by (simp add: wellfounded_on_def, blast)
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subsubsection {*Well-founded relations*}
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lemma  (in M_basic) wellfounded_on_iff_wellfounded:
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     "wellfounded_on(M,A,r) <-> wellfounded(M, r \<inter> A*A)"
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apply (simp add: wellfounded_on_def wellfounded_def, safe)
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 apply blast 
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apply (drule_tac x=x in rspec, assumption, blast) 
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done
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lemma (in M_basic) wellfounded_on_imp_wellfounded:
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     "[|wellfounded_on(M,A,r); r \<subseteq> A*A|] ==> wellfounded(M,r)"
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by (simp add: wellfounded_on_iff_wellfounded subset_Int_iff)
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lemma (in M_basic) wellfounded_on_field_imp_wellfounded:
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     "wellfounded_on(M, field(r), r) ==> wellfounded(M,r)"
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by (simp add: wellfounded_def wellfounded_on_iff_wellfounded, fast)
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lemma (in M_basic) wellfounded_iff_wellfounded_on_field:
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     "M(r) ==> wellfounded(M,r) <-> wellfounded_on(M, field(r), r)"
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by (blast intro: wellfounded_imp_wellfounded_on
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                 wellfounded_on_field_imp_wellfounded)
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(*Consider the least z in domain(r) such that P(z) does not hold...*)
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lemma (in M_basic) wellfounded_induct: 
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     "[| wellfounded(M,r); M(a); M(r); separation(M, \<lambda>x. ~P(x));  
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         \<forall>x. M(x) & (\<forall>y. <y,x> \<in> r --> P(y)) --> P(x) |]
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      ==> P(a)";
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apply (simp (no_asm_use) add: wellfounded_def)
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apply (drule_tac x="{z \<in> domain(r). ~P(z)}" in rspec)
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apply (blast dest: transM)+
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done
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lemma (in M_basic) wellfounded_on_induct: 
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     "[| a\<in>A;  wellfounded_on(M,A,r);  M(A);  
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       separation(M, \<lambda>x. x\<in>A --> ~P(x));  
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       \<forall>x\<in>A. M(x) & (\<forall>y\<in>A. <y,x> \<in> r --> P(y)) --> P(x) |]
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      ==> P(a)";
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apply (simp (no_asm_use) add: wellfounded_on_def)
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apply (drule_tac x="{z\<in>A. z\<in>A --> ~P(z)}" in rspec)
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apply (blast intro: transM)+
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done
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subsubsection {*Kunen's lemma IV 3.14, page 123*}
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lemma (in M_basic) linear_imp_relativized: 
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     "linear(A,r) ==> linear_rel(M,A,r)" 
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by (simp add: linear_def linear_rel_def) 
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lemma (in M_basic) trans_on_imp_relativized: 
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     "trans[A](r) ==> transitive_rel(M,A,r)" 
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by (unfold transitive_rel_def trans_on_def, blast) 
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lemma (in M_basic) wf_on_imp_relativized: 
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     "wf[A](r) ==> wellfounded_on(M,A,r)" 
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apply (simp add: wellfounded_on_def wf_def wf_on_def, clarify) 
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apply (drule_tac x=x in spec, blast) 
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done
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lemma (in M_basic) wf_imp_relativized: 
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     "wf(r) ==> wellfounded(M,r)" 
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apply (simp add: wellfounded_def wf_def, clarify) 
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apply (drule_tac x=x in spec, blast) 
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done
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lemma (in M_basic) well_ord_imp_relativized: 
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     "well_ord(A,r) ==> wellordered(M,A,r)" 
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by (simp add: wellordered_def well_ord_def tot_ord_def part_ord_def
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       linear_imp_relativized trans_on_imp_relativized wf_on_imp_relativized)
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subsection{* Relativized versions of order-isomorphisms and order types *}
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lemma (in M_basic) order_isomorphism_abs [simp]: 
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     "[| M(A); M(B); M(f) |] 
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      ==> order_isomorphism(M,A,r,B,s,f) <-> f \<in> ord_iso(A,r,B,s)"
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by (simp add: apply_closed order_isomorphism_def ord_iso_def)
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lemma (in M_basic) pred_set_abs [simp]: 
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     "[| M(r); M(B) |] ==> pred_set(M,A,x,r,B) <-> B = Order.pred(A,x,r)"
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apply (simp add: pred_set_def Order.pred_def)
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apply (blast dest: transM) 
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done
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lemma (in M_basic) pred_closed [intro,simp]: 
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     "[| M(A); M(r); M(x) |] ==> M(Order.pred(A,x,r))"
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apply (simp add: Order.pred_def) 
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apply (insert pred_separation [of r x], simp) 
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done
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lemma (in M_basic) membership_abs [simp]: 
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     "[| M(r); M(A) |] ==> membership(M,A,r) <-> r = Memrel(A)"
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apply (simp add: membership_def Memrel_def, safe)
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  apply (rule equalityI) 
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   apply clarify 
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   apply (frule transM, assumption)
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   apply blast
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  apply clarify 
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  apply (subgoal_tac "M(<xb,ya>)", blast) 
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  apply (blast dest: transM) 
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 apply auto 
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done
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lemma (in M_basic) M_Memrel_iff:
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     "M(A) ==> 
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      Memrel(A) = {z \<in> A*A. \<exists>x[M]. \<exists>y[M]. z = \<langle>x,y\<rangle> & x \<in> y}"
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apply (simp add: Memrel_def) 
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apply (blast dest: transM)
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done 
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lemma (in M_basic) Memrel_closed [intro,simp]: 
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     "M(A) ==> M(Memrel(A))"
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apply (simp add: M_Memrel_iff) 
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apply (insert Memrel_separation, simp)
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done
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subsection {* Main results of Kunen, Chapter 1 section 6 *}
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text{*Subset properties-- proved outside the locale*}
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lemma linear_rel_subset: 
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    "[| linear_rel(M,A,r);  B<=A |] ==> linear_rel(M,B,r)"
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by (unfold linear_rel_def, blast)
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lemma transitive_rel_subset: 
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    "[| transitive_rel(M,A,r);  B<=A |] ==> transitive_rel(M,B,r)"
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by (unfold transitive_rel_def, blast)
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lemma wellfounded_on_subset: 
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    "[| wellfounded_on(M,A,r);  B<=A |] ==> wellfounded_on(M,B,r)"
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by (unfold wellfounded_on_def subset_def, blast)
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lemma wellordered_subset: 
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    "[| wellordered(M,A,r);  B<=A |] ==> wellordered(M,B,r)"
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apply (unfold wellordered_def)
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apply (blast intro: linear_rel_subset transitive_rel_subset 
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		    wellfounded_on_subset)
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done
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text{*Inductive argument for Kunen's Lemma 6.1, etc.
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      Simple proof from Halmos, page 72*}
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lemma  (in M_basic) wellordered_iso_subset_lemma: 
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     "[| wellordered(M,A,r);  f \<in> ord_iso(A,r, A',r);  A'<= A;  y \<in> A;  
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       M(A);  M(f);  M(r) |] ==> ~ <f`y, y> \<in> r"
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apply (unfold wellordered_def ord_iso_def)
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apply (elim conjE CollectE) 
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apply (erule wellfounded_on_induct, assumption+)
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 apply (insert well_ord_iso_separation [of A f r])
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 apply (simp, clarify) 
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apply (drule_tac a = x in bij_is_fun [THEN apply_type], assumption, blast)
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done
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text{*Kunen's Lemma 6.1: there's no order-isomorphism to an initial segment
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      of a well-ordering*}
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lemma (in M_basic) wellordered_iso_predD:
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     "[| wellordered(M,A,r);  f \<in> ord_iso(A, r, Order.pred(A,x,r), r);  
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       M(A);  M(f);  M(r) |] ==> x \<notin> A"
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apply (rule notI) 
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apply (frule wellordered_iso_subset_lemma, assumption)
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apply (auto elim: predE)  
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(*Now we know  ~ (f`x < x) *)
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apply (drule ord_iso_is_bij [THEN bij_is_fun, THEN apply_type], assumption)
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(*Now we also know f`x  \<in> pred(A,x,r);  contradiction! *)
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apply (simp add: Order.pred_def)
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done
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lemma (in M_basic) wellordered_iso_pred_eq_lemma:
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     "[| f \<in> \<langle>Order.pred(A,y,r), r\<rangle> \<cong> \<langle>Order.pred(A,x,r), r\<rangle>;
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       wellordered(M,A,r); x\<in>A; y\<in>A; M(A); M(f); M(r) |] ==> <x,y> \<notin> r"
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apply (frule wellordered_is_trans_on, assumption)
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apply (rule notI) 
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apply (drule_tac x2=y and x=x and r2=r in 
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         wellordered_subset [OF _ pred_subset, THEN wellordered_iso_predD]) 
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apply (simp add: trans_pred_pred_eq) 
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apply (blast intro: predI dest: transM)+
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done
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text{*Simple consequence of Lemma 6.1*}
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lemma (in M_basic) wellordered_iso_pred_eq:
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     "[| wellordered(M,A,r);
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       f \<in> ord_iso(Order.pred(A,a,r), r, Order.pred(A,c,r), r);   
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       M(A);  M(f);  M(r);  a\<in>A;  c\<in>A |] ==> a=c"
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apply (frule wellordered_is_trans_on, assumption)
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apply (frule wellordered_is_linear, assumption)
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apply (erule_tac x=a and y=c in linearE, auto) 
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apply (drule ord_iso_sym)
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(*two symmetric cases*)
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apply (blast dest: wellordered_iso_pred_eq_lemma)+ 
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done
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lemma (in M_basic) wellfounded_on_asym:
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     "[| wellfounded_on(M,A,r);  <a,x>\<in>r;  a\<in>A; x\<in>A;  M(A) |] ==> <x,a>\<notin>r"
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apply (simp add: wellfounded_on_def) 
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apply (drule_tac x="{x,a}" in rspec) 
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apply (blast dest: transM)+
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done
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lemma (in M_basic) wellordered_asym:
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     "[| wellordered(M,A,r);  <a,x>\<in>r;  a\<in>A; x\<in>A;  M(A) |] ==> <x,a>\<notin>r"
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by (simp add: wellordered_def, blast dest: wellfounded_on_asym)
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text{*Can't use @{text well_ord_iso_preserving} because it needs the
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strong premise @{term "well_ord(A,r)"}*}
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lemma (in M_basic) ord_iso_pred_imp_lt:
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     "[| f \<in> ord_iso(Order.pred(A,x,r), r, i, Memrel(i));
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         g \<in> ord_iso(Order.pred(A,y,r), r, j, Memrel(j));
paulson@13628
   294
         wellordered(M,A,r);  x \<in> A;  y \<in> A; M(A); M(r); M(f); M(g); M(j);
paulson@13628
   295
         Ord(i); Ord(j); \<langle>x,y\<rangle> \<in> r |]
paulson@13223
   296
      ==> i < j"
paulson@13223
   297
apply (frule wellordered_is_trans_on, assumption)
paulson@13223
   298
apply (frule_tac y=y in transM, assumption) 
paulson@13223
   299
apply (rule_tac i=i and j=j in Ord_linear_lt, auto)  
paulson@13223
   300
txt{*case @{term "i=j"} yields a contradiction*}
paulson@13223
   301
 apply (rule_tac x1=x and A1="Order.pred(A,y,r)" in 
paulson@13223
   302
          wellordered_iso_predD [THEN notE]) 
paulson@13223
   303
   apply (blast intro: wellordered_subset [OF _ pred_subset]) 
paulson@13223
   304
  apply (simp add: trans_pred_pred_eq)
paulson@13223
   305
  apply (blast intro: Ord_iso_implies_eq ord_iso_sym ord_iso_trans) 
paulson@13223
   306
 apply (simp_all add: pred_iff pred_closed converse_closed comp_closed)
paulson@13223
   307
txt{*case @{term "j<i"} also yields a contradiction*}
paulson@13223
   308
apply (frule restrict_ord_iso2, assumption+) 
paulson@13223
   309
apply (frule ord_iso_sym [THEN ord_iso_is_bij, THEN bij_is_fun]) 
paulson@13223
   310
apply (frule apply_type, blast intro: ltD) 
paulson@13223
   311
  --{*thus @{term "converse(f)`j \<in> Order.pred(A,x,r)"}*}
paulson@13223
   312
apply (simp add: pred_iff) 
paulson@13223
   313
apply (subgoal_tac
paulson@13299
   314
       "\<exists>h[M]. h \<in> ord_iso(Order.pred(A,y,r), r, 
paulson@13223
   315
                               Order.pred(A, converse(f)`j, r), r)")
paulson@13223
   316
 apply (clarify, frule wellordered_iso_pred_eq, assumption+)
paulson@13223
   317
 apply (blast dest: wellordered_asym)  
paulson@13299
   318
apply (intro rexI)
paulson@13299
   319
 apply (blast intro: Ord_iso_implies_eq ord_iso_sym ord_iso_trans)+
paulson@13223
   320
done
paulson@13223
   321
paulson@13223
   322
paulson@13223
   323
lemma ord_iso_converse1:
paulson@13223
   324
     "[| f: ord_iso(A,r,B,s);  <b, f`a>: s;  a:A;  b:B |] 
paulson@13223
   325
      ==> <converse(f) ` b, a> : r"
paulson@13223
   326
apply (frule ord_iso_converse, assumption+) 
paulson@13223
   327
apply (blast intro: ord_iso_is_bij [THEN bij_is_fun, THEN apply_funtype]) 
paulson@13223
   328
apply (simp add: left_inverse_bij [OF ord_iso_is_bij])
paulson@13223
   329
done
paulson@13223
   330
paulson@13223
   331
paulson@13223
   332
subsection {* Order Types: A Direct Construction by Replacement*}
paulson@13223
   333
paulson@13223
   334
text{*This follows Kunen's Theorem I 7.6, page 17.*}
paulson@13223
   335
paulson@13223
   336
constdefs
paulson@13223
   337
  
paulson@13223
   338
  obase :: "[i=>o,i,i,i] => o"
paulson@13223
   339
       --{*the domain of @{text om}, eventually shown to equal @{text A}*}
paulson@13223
   340
   "obase(M,A,r,z) == 
paulson@13293
   341
	\<forall>a[M]. 
paulson@13293
   342
         a \<in> z <-> 
paulson@13628
   343
          (a\<in>A & (\<exists>x[M]. \<exists>g[M]. Ord(x) & 
paulson@13628
   344
                   order_isomorphism(M,Order.pred(A,a,r),r,x,Memrel(x),g)))"
paulson@13223
   345
paulson@13223
   346
paulson@13223
   347
  omap :: "[i=>o,i,i,i] => o"  
paulson@13223
   348
    --{*the function that maps wosets to order types*}
paulson@13223
   349
   "omap(M,A,r,f) == 
paulson@13293
   350
	\<forall>z[M].
paulson@13293
   351
         z \<in> f <-> 
paulson@13299
   352
          (\<exists>a[M]. a\<in>A & 
paulson@13306
   353
           (\<exists>x[M]. \<exists>g[M]. \<exists>mx[M]. \<exists>par[M]. 
paulson@13306
   354
                ordinal(M,x) & pair(M,a,x,z) & membership(M,x,mx) & 
paulson@13306
   355
                pred_set(M,A,a,r,par) & order_isomorphism(M,par,r,x,mx,g)))"
paulson@13223
   356
paulson@13223
   357
paulson@13223
   358
  otype :: "[i=>o,i,i,i] => o"  --{*the order types themselves*}
paulson@13299
   359
   "otype(M,A,r,i) == \<exists>f[M]. omap(M,A,r,f) & is_range(M,f,i)"
paulson@13223
   360
paulson@13223
   361
paulson@13223
   362
paulson@13564
   363
lemma (in M_basic) obase_iff:
paulson@13223
   364
     "[| M(A); M(r); M(z) |] 
paulson@13223
   365
      ==> obase(M,A,r,z) <-> 
paulson@13306
   366
          z = {a\<in>A. \<exists>x[M]. \<exists>g[M]. Ord(x) & 
paulson@13223
   367
                          g \<in> ord_iso(Order.pred(A,a,r),r,x,Memrel(x))}"
paulson@13223
   368
apply (simp add: obase_def Memrel_closed pred_closed)
paulson@13223
   369
apply (rule iffI) 
paulson@13223
   370
 prefer 2 apply blast 
paulson@13223
   371
apply (rule equalityI) 
paulson@13615
   372
 apply (clarify, frule transM, assumption, simp) 
paulson@13223
   373
apply (clarify, frule transM, assumption, force)
paulson@13223
   374
done
paulson@13223
   375
paulson@13223
   376
text{*Can also be proved with the premise @{term "M(z)"} instead of
paulson@13223
   377
      @{term "M(f)"}, but that version is less useful.*}
paulson@13564
   378
lemma (in M_basic) omap_iff:
paulson@13223
   379
     "[| omap(M,A,r,f); M(A); M(r); M(f) |] 
paulson@13223
   380
      ==> z \<in> f <->
paulson@13306
   381
      (\<exists>a\<in>A. \<exists>x[M]. \<exists>g[M]. z = <a,x> & Ord(x) & 
paulson@13306
   382
                        g \<in> ord_iso(Order.pred(A,a,r),r,x,Memrel(x)))"
paulson@13223
   383
apply (simp add: omap_def Memrel_closed pred_closed) 
paulson@13293
   384
apply (rule iffI)
paulson@13293
   385
 apply (drule_tac [2] x=z in rspec)
paulson@13293
   386
 apply (drule_tac x=z in rspec)
paulson@13293
   387
 apply (blast dest: transM)+
paulson@13223
   388
done
paulson@13223
   389
paulson@13564
   390
lemma (in M_basic) omap_unique:
paulson@13223
   391
     "[| omap(M,A,r,f); omap(M,A,r,f'); M(A); M(r); M(f); M(f') |] ==> f' = f" 
paulson@13223
   392
apply (rule equality_iffI) 
paulson@13223
   393
apply (simp add: omap_iff) 
paulson@13223
   394
done
paulson@13223
   395
paulson@13564
   396
lemma (in M_basic) omap_yields_Ord:
paulson@13223
   397
     "[| omap(M,A,r,f); \<langle>a,x\<rangle> \<in> f; M(a); M(x) |]  ==> Ord(x)"
berghofe@13611
   398
  by (simp add: omap_def)
paulson@13223
   399
paulson@13564
   400
lemma (in M_basic) otype_iff:
paulson@13223
   401
     "[| otype(M,A,r,i); M(A); M(r); M(i) |] 
paulson@13223
   402
      ==> x \<in> i <-> 
paulson@13306
   403
          (M(x) & Ord(x) & 
paulson@13306
   404
           (\<exists>a\<in>A. \<exists>g[M]. g \<in> ord_iso(Order.pred(A,a,r),r,x,Memrel(x))))"
paulson@13306
   405
apply (auto simp add: omap_iff otype_def)
paulson@13306
   406
 apply (blast intro: transM) 
paulson@13306
   407
apply (rule rangeI) 
paulson@13223
   408
apply (frule transM, assumption)
paulson@13223
   409
apply (simp add: omap_iff, blast)
paulson@13223
   410
done
paulson@13223
   411
paulson@13564
   412
lemma (in M_basic) otype_eq_range:
paulson@13306
   413
     "[| omap(M,A,r,f); otype(M,A,r,i); M(A); M(r); M(f); M(i) |] 
paulson@13306
   414
      ==> i = range(f)"
paulson@13223
   415
apply (auto simp add: otype_def omap_iff)
paulson@13223
   416
apply (blast dest: omap_unique) 
paulson@13223
   417
done
paulson@13223
   418
paulson@13223
   419
paulson@13564
   420
lemma (in M_basic) Ord_otype:
paulson@13223
   421
     "[| otype(M,A,r,i); trans[A](r); M(A); M(r); M(i) |] ==> Ord(i)"
paulson@13223
   422
apply (rule OrdI) 
paulson@13223
   423
prefer 2 
paulson@13223
   424
    apply (simp add: Ord_def otype_def omap_def) 
paulson@13223
   425
    apply clarify 
paulson@13223
   426
    apply (frule pair_components_in_M, assumption) 
paulson@13223
   427
    apply blast 
paulson@13223
   428
apply (auto simp add: Transset_def otype_iff) 
paulson@13306
   429
  apply (blast intro: transM)
paulson@13306
   430
 apply (blast intro: Ord_in_Ord) 
paulson@13223
   431
apply (rename_tac y a g)
paulson@13223
   432
apply (frule ord_iso_sym [THEN ord_iso_is_bij, THEN bij_is_fun, 
paulson@13223
   433
			  THEN apply_funtype],  assumption)  
paulson@13223
   434
apply (rule_tac x="converse(g)`y" in bexI)
paulson@13223
   435
 apply (frule_tac a="converse(g) ` y" in ord_iso_restrict_pred, assumption) 
paulson@13223
   436
apply (safe elim!: predE) 
paulson@13306
   437
apply (blast intro: restrict_ord_iso ord_iso_sym ltI dest: transM)
paulson@13223
   438
done
paulson@13223
   439
paulson@13564
   440
lemma (in M_basic) domain_omap:
paulson@13223
   441
     "[| omap(M,A,r,f);  obase(M,A,r,B); M(A); M(r); M(B); M(f) |] 
paulson@13223
   442
      ==> domain(f) = B"
paulson@13223
   443
apply (simp add: domain_closed obase_iff) 
paulson@13223
   444
apply (rule equality_iffI) 
paulson@13223
   445
apply (simp add: domain_iff omap_iff, blast) 
paulson@13223
   446
done
paulson@13223
   447
paulson@13564
   448
lemma (in M_basic) omap_subset: 
paulson@13223
   449
     "[| omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   450
       M(A); M(r); M(f); M(B); M(i) |] ==> f \<subseteq> B * i"
paulson@13615
   451
apply clarify 
paulson@13223
   452
apply (simp add: omap_iff obase_iff) 
paulson@13223
   453
apply (force simp add: otype_iff) 
paulson@13223
   454
done
paulson@13223
   455
paulson@13564
   456
lemma (in M_basic) omap_funtype: 
paulson@13223
   457
     "[| omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   458
       M(A); M(r); M(f); M(B); M(i) |] ==> f \<in> B -> i"
paulson@13223
   459
apply (simp add: domain_omap omap_subset Pi_iff function_def omap_iff) 
paulson@13223
   460
apply (blast intro: Ord_iso_implies_eq ord_iso_sym ord_iso_trans) 
paulson@13223
   461
done
paulson@13223
   462
paulson@13223
   463
paulson@13564
   464
lemma (in M_basic) wellordered_omap_bij:
paulson@13223
   465
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   466
       M(A); M(r); M(f); M(B); M(i) |] ==> f \<in> bij(B,i)"
paulson@13223
   467
apply (insert omap_funtype [of A r f B i]) 
paulson@13223
   468
apply (auto simp add: bij_def inj_def) 
paulson@13223
   469
prefer 2  apply (blast intro: fun_is_surj dest: otype_eq_range) 
paulson@13339
   470
apply (frule_tac a=w in apply_Pair, assumption) 
paulson@13339
   471
apply (frule_tac a=x in apply_Pair, assumption) 
paulson@13223
   472
apply (simp add: omap_iff) 
paulson@13223
   473
apply (blast intro: wellordered_iso_pred_eq ord_iso_sym ord_iso_trans) 
paulson@13223
   474
done
paulson@13223
   475
paulson@13223
   476
paulson@13223
   477
text{*This is not the final result: we must show @{term "oB(A,r) = A"}*}
paulson@13564
   478
lemma (in M_basic) omap_ord_iso:
paulson@13223
   479
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   480
       M(A); M(r); M(f); M(B); M(i) |] ==> f \<in> ord_iso(B,r,i,Memrel(i))"
paulson@13223
   481
apply (rule ord_isoI)
paulson@13223
   482
 apply (erule wellordered_omap_bij, assumption+) 
paulson@13223
   483
apply (insert omap_funtype [of A r f B i], simp) 
paulson@13339
   484
apply (frule_tac a=x in apply_Pair, assumption) 
paulson@13339
   485
apply (frule_tac a=y in apply_Pair, assumption) 
paulson@13223
   486
apply (auto simp add: omap_iff)
paulson@13223
   487
 txt{*direction 1: assuming @{term "\<langle>x,y\<rangle> \<in> r"}*}
paulson@13223
   488
 apply (blast intro: ltD ord_iso_pred_imp_lt)
paulson@13223
   489
 txt{*direction 2: proving @{term "\<langle>x,y\<rangle> \<in> r"} using linearity of @{term r}*}
paulson@13223
   490
apply (rename_tac x y g ga) 
paulson@13223
   491
apply (frule wellordered_is_linear, assumption, 
paulson@13223
   492
       erule_tac x=x and y=y in linearE, assumption+) 
paulson@13223
   493
txt{*the case @{term "x=y"} leads to immediate contradiction*} 
paulson@13223
   494
apply (blast elim: mem_irrefl) 
paulson@13223
   495
txt{*the case @{term "\<langle>y,x\<rangle> \<in> r"}: handle like the opposite direction*}
paulson@13223
   496
apply (blast dest: ord_iso_pred_imp_lt ltD elim: mem_asym) 
paulson@13223
   497
done
paulson@13223
   498
paulson@13564
   499
lemma (in M_basic) Ord_omap_image_pred:
paulson@13223
   500
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   501
       M(A); M(r); M(f); M(B); M(i); b \<in> A |] ==> Ord(f `` Order.pred(A,b,r))"
paulson@13223
   502
apply (frule wellordered_is_trans_on, assumption)
paulson@13223
   503
apply (rule OrdI) 
paulson@13223
   504
	prefer 2 apply (simp add: image_iff omap_iff Ord_def, blast) 
paulson@13223
   505
txt{*Hard part is to show that the image is a transitive set.*}
paulson@13223
   506
apply (simp add: Transset_def, clarify) 
paulson@13223
   507
apply (simp add: image_iff pred_iff apply_iff [OF omap_funtype [of A r f B i]])
paulson@13223
   508
apply (rename_tac c j, clarify)
paulson@13223
   509
apply (frule omap_funtype [of A r f B, THEN apply_funtype], assumption+)
paulson@13223
   510
apply (subgoal_tac "j : i") 
paulson@13223
   511
	prefer 2 apply (blast intro: Ord_trans Ord_otype)
paulson@13223
   512
apply (subgoal_tac "converse(f) ` j : B") 
paulson@13223
   513
	prefer 2 
paulson@13223
   514
	apply (blast dest: wellordered_omap_bij [THEN bij_converse_bij, 
paulson@13223
   515
                                      THEN bij_is_fun, THEN apply_funtype])
paulson@13223
   516
apply (rule_tac x="converse(f) ` j" in bexI) 
paulson@13223
   517
 apply (simp add: right_inverse_bij [OF wellordered_omap_bij]) 
paulson@13223
   518
apply (intro predI conjI)
paulson@13223
   519
 apply (erule_tac b=c in trans_onD) 
paulson@13223
   520
 apply (rule ord_iso_converse1 [OF omap_ord_iso [of A r f B i]])
paulson@13223
   521
apply (auto simp add: obase_iff)
paulson@13223
   522
done
paulson@13223
   523
paulson@13564
   524
lemma (in M_basic) restrict_omap_ord_iso:
paulson@13223
   525
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i); 
paulson@13223
   526
       D \<subseteq> B; M(A); M(r); M(f); M(B); M(i) |] 
paulson@13223
   527
      ==> restrict(f,D) \<in> (\<langle>D,r\<rangle> \<cong> \<langle>f``D, Memrel(f``D)\<rangle>)"
paulson@13223
   528
apply (frule ord_iso_restrict_image [OF omap_ord_iso [of A r f B i]], 
paulson@13223
   529
       assumption+)
paulson@13223
   530
apply (drule ord_iso_sym [THEN subset_ord_iso_Memrel]) 
paulson@13223
   531
apply (blast dest: subsetD [OF omap_subset]) 
paulson@13223
   532
apply (drule ord_iso_sym, simp) 
paulson@13223
   533
done
paulson@13223
   534
paulson@13564
   535
lemma (in M_basic) obase_equals: 
paulson@13223
   536
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i);
paulson@13223
   537
       M(A); M(r); M(f); M(B); M(i) |] ==> B = A"
paulson@13223
   538
apply (rule equalityI, force simp add: obase_iff, clarify) 
paulson@13223
   539
apply (subst obase_iff [of A r B, THEN iffD1], assumption+, simp) 
paulson@13223
   540
apply (frule wellordered_is_wellfounded_on, assumption)
paulson@13223
   541
apply (erule wellfounded_on_induct, assumption+)
paulson@13306
   542
 apply (frule obase_equals_separation [of A r], assumption) 
paulson@13306
   543
 apply (simp, clarify) 
paulson@13223
   544
apply (rename_tac b) 
paulson@13223
   545
apply (subgoal_tac "Order.pred(A,b,r) <= B") 
paulson@13306
   546
 apply (blast intro!: restrict_omap_ord_iso Ord_omap_image_pred)
paulson@13306
   547
apply (force simp add: pred_iff obase_iff)  
paulson@13223
   548
done
paulson@13223
   549
paulson@13223
   550
paulson@13223
   551
paulson@13223
   552
text{*Main result: @{term om} gives the order-isomorphism 
paulson@13223
   553
      @{term "\<langle>A,r\<rangle> \<cong> \<langle>i, Memrel(i)\<rangle>"} *}
paulson@13564
   554
theorem (in M_basic) omap_ord_iso_otype:
paulson@13223
   555
     "[| wellordered(M,A,r); omap(M,A,r,f); obase(M,A,r,B); otype(M,A,r,i);
paulson@13223
   556
       M(A); M(r); M(f); M(B); M(i) |] ==> f \<in> ord_iso(A, r, i, Memrel(i))"
paulson@13223
   557
apply (frule omap_ord_iso, assumption+) 
paulson@13223
   558
apply (frule obase_equals, assumption+, blast) 
paulson@13293
   559
done 
paulson@13223
   560
paulson@13564
   561
lemma (in M_basic) obase_exists:
paulson@13293
   562
     "[| M(A); M(r) |] ==> \<exists>z[M]. obase(M,A,r,z)"
paulson@13223
   563
apply (simp add: obase_def) 
paulson@13223
   564
apply (insert obase_separation [of A r])
paulson@13223
   565
apply (simp add: separation_def)  
paulson@13223
   566
done
paulson@13223
   567
paulson@13564
   568
lemma (in M_basic) omap_exists:
paulson@13293
   569
     "[| M(A); M(r) |] ==> \<exists>z[M]. omap(M,A,r,z)"
paulson@13223
   570
apply (insert obase_exists [of A r]) 
paulson@13223
   571
apply (simp add: omap_def) 
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   572
apply (insert omap_replacement [of A r])
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   573
apply (simp add: strong_replacement_def, clarify) 
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   574
apply (drule_tac x=x in rspec, clarify) 
paulson@13223
   575
apply (simp add: Memrel_closed pred_closed obase_iff)
paulson@13223
   576
apply (erule impE) 
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   577
 apply (clarsimp simp add: univalent_def)
paulson@13223
   578
 apply (blast intro: Ord_iso_implies_eq ord_iso_sym ord_iso_trans, clarify)  
paulson@13293
   579
apply (rule_tac x=Y in rexI) 
paulson@13293
   580
apply (simp add: Memrel_closed pred_closed obase_iff, blast, assumption)
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   581
done
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   582
paulson@13293
   583
declare rall_simps [simp] rex_simps [simp]
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   584
paulson@13564
   585
lemma (in M_basic) otype_exists:
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   586
     "[| wellordered(M,A,r); M(A); M(r) |] ==> \<exists>i[M]. otype(M,A,r,i)"
paulson@13293
   587
apply (insert omap_exists [of A r])  
paulson@13293
   588
apply (simp add: otype_def, safe)
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   589
apply (rule_tac x="range(x)" in rexI) 
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   590
apply blast+
paulson@13223
   591
done
paulson@13223
   592
paulson@13564
   593
theorem (in M_basic) omap_ord_iso_otype':
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   594
     "[| wellordered(M,A,r); M(A); M(r) |]
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   595
      ==> \<exists>f[M]. (\<exists>i[M]. Ord(i) & f \<in> ord_iso(A, r, i, Memrel(i)))"
paulson@13223
   596
apply (insert obase_exists [of A r] omap_exists [of A r] otype_exists [of A r], simp, clarify)
paulson@13299
   597
apply (rename_tac i) 
paulson@13223
   598
apply (subgoal_tac "Ord(i)", blast intro: omap_ord_iso_otype) 
paulson@13223
   599
apply (rule Ord_otype) 
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   600
    apply (force simp add: otype_def range_closed) 
paulson@13223
   601
   apply (simp_all add: wellordered_is_trans_on) 
paulson@13223
   602
done
paulson@13223
   603
paulson@13564
   604
lemma (in M_basic) ordertype_exists:
paulson@13223
   605
     "[| wellordered(M,A,r); M(A); M(r) |]
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   606
      ==> \<exists>f[M]. (\<exists>i[M]. Ord(i) & f \<in> ord_iso(A, r, i, Memrel(i)))"
paulson@13223
   607
apply (insert obase_exists [of A r] omap_exists [of A r] otype_exists [of A r], simp, clarify)
paulson@13299
   608
apply (rename_tac i) 
wenzelm@13428
   609
apply (subgoal_tac "Ord(i)", blast intro: omap_ord_iso_otype')
paulson@13223
   610
apply (rule Ord_otype) 
paulson@13223
   611
    apply (force simp add: otype_def range_closed) 
paulson@13223
   612
   apply (simp_all add: wellordered_is_trans_on) 
paulson@13223
   613
done
paulson@13223
   614
paulson@13223
   615
paulson@13564
   616
lemma (in M_basic) relativized_imp_well_ord: 
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   617
     "[| wellordered(M,A,r); M(A); M(r) |] ==> well_ord(A,r)" 
paulson@13223
   618
apply (insert ordertype_exists [of A r], simp)
paulson@13505
   619
apply (blast intro: well_ord_ord_iso well_ord_Memrel)  
paulson@13223
   620
done
paulson@13223
   621
paulson@13223
   622
subsection {*Kunen's theorem 5.4, poage 127*}
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   623
paulson@13223
   624
text{*(a) The notion of Wellordering is absolute*}
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   625
theorem (in M_basic) well_ord_abs [simp]: 
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   626
     "[| M(A); M(r) |] ==> wellordered(M,A,r) <-> well_ord(A,r)" 
paulson@13223
   627
by (blast intro: well_ord_imp_relativized relativized_imp_well_ord)  
paulson@13223
   628
paulson@13223
   629
paulson@13223
   630
text{*(b) Order types are absolute*}
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   631
lemma (in M_basic) 
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   632
     "[| wellordered(M,A,r); f \<in> ord_iso(A, r, i, Memrel(i));
paulson@13223
   633
       M(A); M(r); M(f); M(i); Ord(i) |] ==> i = ordertype(A,r)"
paulson@13223
   634
by (blast intro: Ord_ordertype relativized_imp_well_ord ordertype_ord_iso
paulson@13223
   635
                 Ord_iso_implies_eq ord_iso_sym ord_iso_trans)
paulson@13223
   636
paulson@13223
   637
end