src/HOL/Dense_Linear_Order.thy
changeset 23453 bf46f5cbdd64
child 23466 886655a150f6
equal deleted inserted replaced
23452:95b70054bb3a 23453:bf46f5cbdd64
       
     1 (*
       
     2     ID:         $Id$
       
     3     Author:     Amine Chaieb, TU Muenchen
       
     4 *)
       
     5 
       
     6 header {* Dense linear order witout endpoints
       
     7   and a quantifier elimination procedure in Ferrante and Rackoff style *}
       
     8 
       
     9 theory Dense_Linear_Order
       
    10 imports Finite_Set
       
    11 uses
       
    12   "Tools/qelim.ML"
       
    13   "Tools/Ferrante_Rackoff/ferrante_rackoff_data.ML"
       
    14   ("Tools/Ferrante_Rackoff/ferrante_rackoff.ML")
       
    15 begin
       
    16 
       
    17 setup Ferrante_Rackoff_Data.setup
       
    18 
       
    19 context Linorder
       
    20 begin
       
    21 
       
    22 text{* Theorems for @{text "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P x \<longleftrightarrow> P\<^bsub>-\<infinity>\<^esub>)"}*}
       
    23 lemma minf_lt:  "\<exists>z . \<forall>x. x \<sqsubset> z \<longrightarrow> (x \<sqsubset> t \<longleftrightarrow> True)" by auto
       
    24 lemma minf_gt: "\<exists>z . \<forall>x. x \<sqsubset> z \<longrightarrow>  (t \<sqsubset> x \<longleftrightarrow>  False)"
       
    25   by (simp add: not_less) (rule exI[where x="t"], auto simp add: less_le)
       
    26 
       
    27 lemma minf_le: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (x \<sqsubseteq> t \<longleftrightarrow> True)" by (auto simp add: less_le)
       
    28 lemma minf_ge: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (t \<sqsubseteq> x \<longleftrightarrow> False)"
       
    29   by (auto simp add: less_le not_less not_le)
       
    30 lemma minf_eq: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (x = t \<longleftrightarrow> False)" by auto
       
    31 lemma minf_neq: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (x \<noteq> t \<longleftrightarrow> True)" by auto
       
    32 lemma minf_P: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P \<longleftrightarrow> P)" by blast
       
    33 
       
    34 text{* Theorems for @{text "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P x \<longleftrightarrow> P\<^bsub>+\<infinity>\<^esub>)"}*}
       
    35 lemma pinf_gt:  "\<exists>z . \<forall>x. z \<sqsubset> x \<longrightarrow> (t \<sqsubset> x \<longleftrightarrow> True)" by auto
       
    36 lemma pinf_lt: "\<exists>z . \<forall>x. z \<sqsubset> x \<longrightarrow>  (x \<sqsubset> t \<longleftrightarrow>  False)"
       
    37   by (simp add: not_less) (rule exI[where x="t"], auto simp add: less_le)
       
    38 
       
    39 lemma pinf_ge: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (t \<sqsubseteq> x \<longleftrightarrow> True)" by (auto simp add: less_le)
       
    40 lemma pinf_le: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (x \<sqsubseteq> t \<longleftrightarrow> False)"
       
    41   by (auto simp add: less_le not_less not_le)
       
    42 lemma pinf_eq: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (x = t \<longleftrightarrow> False)" by auto
       
    43 lemma pinf_neq: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (x \<noteq> t \<longleftrightarrow> True)" by auto
       
    44 lemma pinf_P: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (P \<longleftrightarrow> P)" by blast
       
    45 
       
    46 lemma nmi_lt: "t \<in> U \<Longrightarrow> \<forall>x. \<not>True \<and> x \<sqsubset> t \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    47 lemma nmi_gt: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and> t \<sqsubset> x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)"
       
    48   by (auto simp add: le_less)
       
    49 lemma  nmi_le: "t \<in> U \<Longrightarrow> \<forall>x. \<not>True \<and> x\<sqsubseteq> t \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    50 lemma  nmi_ge: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and> t\<sqsubseteq> x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    51 lemma  nmi_eq: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and>  x = t \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    52 lemma  nmi_neq: "t \<in> U \<Longrightarrow>\<forall>x. \<not>True \<and> x \<noteq> t \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    53 lemma  nmi_P: "\<forall> x. ~P \<and> P \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    54 lemma  nmi_conj: "\<lbrakk>\<forall>x. \<not>P1' \<and> P1 x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x) ;
       
    55   \<forall>x. \<not>P2' \<and> P2 x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)\<rbrakk> \<Longrightarrow>
       
    56   \<forall>x. \<not>(P1' \<and> P2') \<and> (P1 x \<and> P2 x) \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    57 lemma  nmi_disj: "\<lbrakk>\<forall>x. \<not>P1' \<and> P1 x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x) ;
       
    58   \<forall>x. \<not>P2' \<and> P2 x \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)\<rbrakk> \<Longrightarrow>
       
    59   \<forall>x. \<not>(P1' \<or> P2') \<and> (P1 x \<or> P2 x) \<longrightarrow>  (\<exists> u\<in> U. u \<sqsubseteq> x)" by auto
       
    60 
       
    61 lemma  npi_lt: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and>  x \<sqsubset> t \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by (auto simp add: le_less)
       
    62 lemma  npi_gt: "t \<in> U \<Longrightarrow> \<forall>x. \<not>True \<and> t \<sqsubset> x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    63 lemma  npi_le: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and>  x \<sqsubseteq> t \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    64 lemma  npi_ge: "t \<in> U \<Longrightarrow> \<forall>x. \<not>True \<and> t \<sqsubseteq> x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    65 lemma  npi_eq: "t \<in> U \<Longrightarrow> \<forall>x. \<not>False \<and>  x = t \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    66 lemma  npi_neq: "t \<in> U \<Longrightarrow> \<forall>x. \<not>True \<and> x \<noteq> t \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u )" by auto
       
    67 lemma  npi_P: "\<forall> x. ~P \<and> P \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    68 lemma  npi_conj: "\<lbrakk>\<forall>x. \<not>P1' \<and> P1 x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u) ;  \<forall>x. \<not>P2' \<and> P2 x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)\<rbrakk>
       
    69   \<Longrightarrow>  \<forall>x. \<not>(P1' \<and> P2') \<and> (P1 x \<and> P2 x) \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    70 lemma  npi_disj: "\<lbrakk>\<forall>x. \<not>P1' \<and> P1 x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u) ; \<forall>x. \<not>P2' \<and> P2 x \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)\<rbrakk>
       
    71   \<Longrightarrow> \<forall>x. \<not>(P1' \<or> P2') \<and> (P1 x \<or> P2 x) \<longrightarrow>  (\<exists> u\<in> U. x \<sqsubseteq> u)" by auto
       
    72 
       
    73 lemma lin_dense_lt: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t \<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> x \<sqsubset> t \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> y \<sqsubset> t)"
       
    74 proof(clarsimp)
       
    75   fix x l u y  assume tU: "t \<in> U" and noU: "\<forall>t. l \<sqsubset> t \<and> t \<sqsubset> u \<longrightarrow> t \<notin> U" and lx: "l \<sqsubset> x"
       
    76     and xu: "x\<sqsubset>u"  and px: "x \<sqsubset> t" and ly: "l\<sqsubset>y" and yu:"y \<sqsubset> u"
       
    77   from tU noU ly yu have tny: "t\<noteq>y" by auto
       
    78   {assume H: "t \<sqsubset> y"
       
    79     from less_trans[OF lx px] less_trans[OF H yu]
       
    80     have "l \<sqsubset> t \<and> t \<sqsubset> u"  by simp
       
    81     with tU noU have "False" by auto}
       
    82   hence "\<not> t \<sqsubset> y"  by auto hence "y \<sqsubseteq> t" by (simp add: not_less)
       
    83   thus "y \<sqsubset> t" using tny by (simp add: less_le)
       
    84 qed
       
    85 
       
    86 lemma lin_dense_gt: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l \<sqsubset> x \<and> x \<sqsubset> u \<and> t \<sqsubset> x \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> t \<sqsubset> y)"
       
    87 proof(clarsimp)
       
    88   fix x l u y
       
    89   assume tU: "t \<in> U" and noU: "\<forall>t. l \<sqsubset> t \<and> t \<sqsubset> u \<longrightarrow> t \<notin> U" and lx: "l \<sqsubset> x" and xu: "x\<sqsubset>u"
       
    90   and px: "t \<sqsubset> x" and ly: "l\<sqsubset>y" and yu:"y \<sqsubset> u"
       
    91   from tU noU ly yu have tny: "t\<noteq>y" by auto
       
    92   {assume H: "y\<sqsubset> t"
       
    93     from less_trans[OF ly H] less_trans[OF px xu] have "l \<sqsubset> t \<and> t \<sqsubset> u" by simp
       
    94     with tU noU have "False" by auto}
       
    95   hence "\<not> y\<sqsubset>t"  by auto hence "t \<sqsubseteq> y" by (auto simp add: not_less)
       
    96   thus "t \<sqsubset> y" using tny by (simp add:less_le)
       
    97 qed
       
    98 
       
    99 lemma lin_dense_le: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> x \<sqsubseteq> t \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> y\<sqsubseteq> t)"
       
   100 proof(clarsimp)
       
   101   fix x l u y
       
   102   assume tU: "t \<in> U" and noU: "\<forall>t. l \<sqsubset> t \<and> t \<sqsubset> u \<longrightarrow> t \<notin> U" and lx: "l \<sqsubset> x" and xu: "x\<sqsubset>u"
       
   103   and px: "x \<sqsubseteq> t" and ly: "l\<sqsubset>y" and yu:"y \<sqsubset> u"
       
   104   from tU noU ly yu have tny: "t\<noteq>y" by auto
       
   105   {assume H: "t \<sqsubset> y"
       
   106     from less_le_trans[OF lx px] less_trans[OF H yu]
       
   107     have "l \<sqsubset> t \<and> t \<sqsubset> u" by simp
       
   108     with tU noU have "False" by auto}
       
   109   hence "\<not> t \<sqsubset> y"  by auto thus "y \<sqsubseteq> t" by (simp add: not_less)
       
   110 qed
       
   111 
       
   112 lemma lin_dense_ge: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> t \<sqsubseteq> x \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> t \<sqsubseteq> y)"
       
   113 proof(clarsimp)
       
   114   fix x l u y
       
   115   assume tU: "t \<in> U" and noU: "\<forall>t. l \<sqsubset> t \<and> t \<sqsubset> u \<longrightarrow> t \<notin> U" and lx: "l \<sqsubset> x" and xu: "x\<sqsubset>u"
       
   116   and px: "t \<sqsubseteq> x" and ly: "l\<sqsubset>y" and yu:"y \<sqsubset> u"
       
   117   from tU noU ly yu have tny: "t\<noteq>y" by auto
       
   118   {assume H: "y\<sqsubset> t"
       
   119     from less_trans[OF ly H] le_less_trans[OF px xu]
       
   120     have "l \<sqsubset> t \<and> t \<sqsubset> u" by simp
       
   121     with tU noU have "False" by auto}
       
   122   hence "\<not> y\<sqsubset>t"  by auto thus "t \<sqsubseteq> y" by (simp add: not_less)
       
   123 qed
       
   124 lemma lin_dense_eq: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> x = t   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> y= t)"  by auto
       
   125 lemma lin_dense_neq: "t \<in> U \<Longrightarrow> \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> x \<noteq> t   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> y\<noteq> t)"  by auto
       
   126 lemma lin_dense_P: "\<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P)"  by auto
       
   127 
       
   128 lemma lin_dense_conj:
       
   129   "\<lbrakk>\<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P1 x
       
   130   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P1 y) ;
       
   131   \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P2 x
       
   132   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P2 y)\<rbrakk> \<Longrightarrow>
       
   133   \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> (P1 x \<and> P2 x)
       
   134   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> (P1 y \<and> P2 y))"
       
   135   by blast
       
   136 lemma lin_dense_disj:
       
   137   "\<lbrakk>\<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P1 x
       
   138   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P1 y) ;
       
   139   \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P2 x
       
   140   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P2 y)\<rbrakk> \<Longrightarrow>
       
   141   \<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> (P1 x \<or> P2 x)
       
   142   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> (P1 y \<or> P2 y))"
       
   143   by blast
       
   144 
       
   145 lemma npmibnd: "\<lbrakk>\<forall>x. \<not> MP \<and> P x \<longrightarrow> (\<exists> u\<in> U. u \<sqsubseteq> x); \<forall>x. \<not>PP \<and> P x \<longrightarrow> (\<exists> u\<in> U. x \<sqsubseteq> u)\<rbrakk>
       
   146   \<Longrightarrow> \<forall>x. \<not> MP \<and> \<not>PP \<and> P x \<longrightarrow> (\<exists> u\<in> U. \<exists> u' \<in> U. u \<sqsubseteq> x \<and> x \<sqsubseteq> u')"
       
   147 by auto
       
   148 
       
   149 lemma finite_set_intervals:
       
   150   assumes px: "P x" and lx: "l \<sqsubseteq> x" and xu: "x \<sqsubseteq> u" and linS: "l\<in> S"
       
   151   and uinS: "u \<in> S" and fS:"finite S" and lS: "\<forall> x\<in> S. l \<sqsubseteq> x" and Su: "\<forall> x\<in> S. x \<sqsubseteq> u"
       
   152   shows "\<exists> a \<in> S. \<exists> b \<in> S. (\<forall> y. a \<sqsubset> y \<and> y \<sqsubset> b \<longrightarrow> y \<notin> S) \<and> a \<sqsubseteq> x \<and> x \<sqsubseteq> b \<and> P x"
       
   153 proof-
       
   154   let ?Mx = "{y. y\<in> S \<and> y \<sqsubseteq> x}"
       
   155   let ?xM = "{y. y\<in> S \<and> x \<sqsubseteq> y}"
       
   156   let ?a = "Max ?Mx"
       
   157   let ?b = "Min ?xM"
       
   158   have MxS: "?Mx \<subseteq> S" by blast
       
   159   hence fMx: "finite ?Mx" using fS finite_subset by auto
       
   160   from lx linS have linMx: "l \<in> ?Mx" by blast
       
   161   hence Mxne: "?Mx \<noteq> {}" by blast
       
   162   have xMS: "?xM \<subseteq> S" by blast
       
   163   hence fxM: "finite ?xM" using fS finite_subset by auto
       
   164   from xu uinS have linxM: "u \<in> ?xM" by blast
       
   165   hence xMne: "?xM \<noteq> {}" by blast
       
   166   have ax:"?a \<sqsubseteq> x" using Mxne fMx by auto
       
   167   have xb:"x \<sqsubseteq> ?b" using xMne fxM by auto
       
   168   have "?a \<in> ?Mx" using Max_in[OF fMx Mxne] by simp hence ainS: "?a \<in> S" using MxS by blast
       
   169   have "?b \<in> ?xM" using Min_in[OF fxM xMne] by simp hence binS: "?b \<in> S" using xMS by blast
       
   170   have noy:"\<forall> y. ?a \<sqsubset> y \<and> y \<sqsubset> ?b \<longrightarrow> y \<notin> S"
       
   171   proof(clarsimp)
       
   172     fix y   assume ay: "?a \<sqsubset> y" and yb: "y \<sqsubset> ?b" and yS: "y \<in> S"
       
   173     from yS have "y\<in> ?Mx \<or> y\<in> ?xM" by (auto simp add: linear)
       
   174     moreover {assume "y \<in> ?Mx" hence "y \<sqsubseteq> ?a" using Mxne fMx by auto with ay have "False" by (simp add: not_le[symmetric])}
       
   175     moreover {assume "y \<in> ?xM" hence "?b \<sqsubseteq> y" using xMne fxM by auto with yb have "False" by (simp add: not_le[symmetric])}
       
   176     ultimately show "False" by blast
       
   177   qed
       
   178   from ainS binS noy ax xb px show ?thesis by blast
       
   179 qed
       
   180 
       
   181 
       
   182 lemma finite_set_intervals2:
       
   183   assumes px: "P x" and lx: "l \<sqsubseteq> x" and xu: "x \<sqsubseteq> u" and linS: "l\<in> S"
       
   184   and uinS: "u \<in> S" and fS:"finite S" and lS: "\<forall> x\<in> S. l \<sqsubseteq> x" and Su: "\<forall> x\<in> S. x \<sqsubseteq> u"
       
   185   shows "(\<exists> s\<in> S. P s) \<or> (\<exists> a \<in> S. \<exists> b \<in> S. (\<forall> y. a \<sqsubset> y \<and> y \<sqsubset> b \<longrightarrow> y \<notin> S) \<and> a \<sqsubset> x \<and> x \<sqsubset> b \<and> P x)"
       
   186 proof-
       
   187   from finite_set_intervals[where P="P", OF px lx xu linS uinS fS lS Su]
       
   188   obtain a and b where
       
   189     as: "a\<in> S" and bs: "b\<in> S" and noS:"\<forall>y. a \<sqsubset> y \<and> y \<sqsubset> b \<longrightarrow> y \<notin> S"
       
   190     and axb: "a \<sqsubseteq> x \<and> x \<sqsubseteq> b \<and> P x"  by auto
       
   191   from axb have "x= a \<or> x= b \<or> (a \<sqsubset> x \<and> x \<sqsubset> b)" by (auto simp add: le_less)
       
   192   thus ?thesis using px as bs noS by blast
       
   193 qed
       
   194 
       
   195 end
       
   196 
       
   197 text {* Linear order without upper bounds *}
       
   198 
       
   199 locale linorder_no_ub = Linorder + assumes gt_ex: "\<forall>x. \<exists>y. x \<sqsubset> y"
       
   200 begin
       
   201 
       
   202 lemma ge_ex: "\<forall>x. \<exists>y. x \<sqsubseteq> y" using gt_ex by auto
       
   203 
       
   204 text {* Theorems for @{text "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (P x \<longleftrightarrow> P\<^bsub>+\<infinity>\<^esub>)"} *}
       
   205 lemma pinf_conj:
       
   206   assumes ex1: "\<exists>z1. \<forall>x. z1 \<sqsubset> x \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   207   and ex2: "\<exists>z2. \<forall>x. z2 \<sqsubset> x \<longrightarrow> (P2 x \<longleftrightarrow> P2')"
       
   208   shows "\<exists>z. \<forall>x. z \<sqsubset>  x \<longrightarrow> ((P1 x \<and> P2 x) \<longleftrightarrow> (P1' \<and> P2'))"
       
   209 proof-
       
   210   from ex1 ex2 obtain z1 and z2 where z1: "\<forall>x. z1 \<sqsubset> x \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   211      and z2: "\<forall>x. z2 \<sqsubset> x \<longrightarrow> (P2 x \<longleftrightarrow> P2')" by blast
       
   212   from gt_ex obtain z where z:"max z1 z2 \<sqsubset> z" by blast
       
   213   from z have zz1: "z1 \<sqsubset> z" and zz2: "z2 \<sqsubset> z" by simp_all
       
   214   {fix x assume H: "z \<sqsubset> x"
       
   215     from less_trans[OF zz1 H] less_trans[OF zz2 H]
       
   216     have "(P1 x \<and> P2 x) \<longleftrightarrow> (P1' \<and> P2')"  using z1 zz1 z2 zz2 by auto
       
   217   }
       
   218   thus ?thesis by blast
       
   219 qed
       
   220 
       
   221 lemma pinf_disj:
       
   222   assumes ex1: "\<exists>z1. \<forall>x. z1 \<sqsubset> x \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   223   and ex2: "\<exists>z2. \<forall>x. z2 \<sqsubset> x \<longrightarrow> (P2 x \<longleftrightarrow> P2')"
       
   224   shows "\<exists>z. \<forall>x. z \<sqsubset>  x \<longrightarrow> ((P1 x \<or> P2 x) \<longleftrightarrow> (P1' \<or> P2'))"
       
   225 proof-
       
   226   from ex1 ex2 obtain z1 and z2 where z1: "\<forall>x. z1 \<sqsubset> x \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   227      and z2: "\<forall>x. z2 \<sqsubset> x \<longrightarrow> (P2 x \<longleftrightarrow> P2')" by blast
       
   228   from gt_ex obtain z where z:"max z1 z2 \<sqsubset> z" by blast
       
   229   from z have zz1: "z1 \<sqsubset> z" and zz2: "z2 \<sqsubset> z" by simp_all
       
   230   {fix x assume H: "z \<sqsubset> x"
       
   231     from less_trans[OF zz1 H] less_trans[OF zz2 H]
       
   232     have "(P1 x \<or> P2 x) \<longleftrightarrow> (P1' \<or> P2')"  using z1 zz1 z2 zz2 by auto
       
   233   }
       
   234   thus ?thesis by blast
       
   235 qed
       
   236 
       
   237 lemma pinf_ex: assumes ex:"\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (P x \<longleftrightarrow> P1)" and p1: P1 shows "\<exists> x. P x"
       
   238 proof-
       
   239   from ex obtain z where z: "\<forall>x. z \<sqsubset> x \<longrightarrow> (P x \<longleftrightarrow> P1)" by blast
       
   240   from gt_ex obtain x where x: "z \<sqsubset> x" by blast
       
   241   from z x p1 show ?thesis by blast
       
   242 qed
       
   243 
       
   244 end
       
   245 
       
   246 text {* Linear order without upper bounds *}
       
   247 
       
   248 locale linorder_no_lb = Linorder + assumes lt_ex: "\<forall>x. \<exists>y. y \<sqsubset> x"
       
   249 begin
       
   250 
       
   251 lemma le_ex: "\<forall>x. \<exists>y. y \<sqsubseteq> x" using lt_ex by auto
       
   252 
       
   253 
       
   254 text {* Theorems for @{text "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P x \<longleftrightarrow> P\<^bsub>-\<infinity>\<^esub>)"} *}
       
   255 lemma minf_conj:
       
   256   assumes ex1: "\<exists>z1. \<forall>x. x \<sqsubset> z1 \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   257   and ex2: "\<exists>z2. \<forall>x. x \<sqsubset> z2 \<longrightarrow> (P2 x \<longleftrightarrow> P2')"
       
   258   shows "\<exists>z. \<forall>x. x \<sqsubset>  z \<longrightarrow> ((P1 x \<and> P2 x) \<longleftrightarrow> (P1' \<and> P2'))"
       
   259 proof-
       
   260   from ex1 ex2 obtain z1 and z2 where z1: "\<forall>x. x \<sqsubset> z1 \<longrightarrow> (P1 x \<longleftrightarrow> P1')"and z2: "\<forall>x. x \<sqsubset> z2 \<longrightarrow> (P2 x \<longleftrightarrow> P2')" by blast
       
   261   from lt_ex obtain z where z:"z \<sqsubset> min z1 z2" by blast
       
   262   from z have zz1: "z \<sqsubset> z1" and zz2: "z \<sqsubset> z2" by simp_all
       
   263   {fix x assume H: "x \<sqsubset> z"
       
   264     from less_trans[OF H zz1] less_trans[OF H zz2]
       
   265     have "(P1 x \<and> P2 x) \<longleftrightarrow> (P1' \<and> P2')"  using z1 zz1 z2 zz2 by auto
       
   266   }
       
   267   thus ?thesis by blast
       
   268 qed
       
   269 
       
   270 lemma minf_disj:
       
   271   assumes ex1: "\<exists>z1. \<forall>x. x \<sqsubset> z1 \<longrightarrow> (P1 x \<longleftrightarrow> P1')"
       
   272   and ex2: "\<exists>z2. \<forall>x. x \<sqsubset> z2 \<longrightarrow> (P2 x \<longleftrightarrow> P2')"
       
   273   shows "\<exists>z. \<forall>x. x \<sqsubset>  z \<longrightarrow> ((P1 x \<or> P2 x) \<longleftrightarrow> (P1' \<or> P2'))"
       
   274 proof-
       
   275   from ex1 ex2 obtain z1 and z2 where z1: "\<forall>x. x \<sqsubset> z1 \<longrightarrow> (P1 x \<longleftrightarrow> P1')"and z2: "\<forall>x. x \<sqsubset> z2 \<longrightarrow> (P2 x \<longleftrightarrow> P2')" by blast
       
   276   from lt_ex obtain z where z:"z \<sqsubset> min z1 z2" by blast
       
   277   from z have zz1: "z \<sqsubset> z1" and zz2: "z \<sqsubset> z2" by simp_all
       
   278   {fix x assume H: "x \<sqsubset> z"
       
   279     from less_trans[OF H zz1] less_trans[OF H zz2]
       
   280     have "(P1 x \<or> P2 x) \<longleftrightarrow> (P1' \<or> P2')"  using z1 zz1 z2 zz2 by auto
       
   281   }
       
   282   thus ?thesis by blast
       
   283 qed
       
   284 
       
   285 lemma minf_ex: assumes ex:"\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P x \<longleftrightarrow> P1)" and p1: P1 shows "\<exists> x. P x"
       
   286 proof-
       
   287   from ex obtain z where z: "\<forall>x. x \<sqsubset> z \<longrightarrow> (P x \<longleftrightarrow> P1)" by blast
       
   288   from lt_ex obtain x where x: "x \<sqsubset> z" by blast
       
   289   from z x p1 show ?thesis by blast
       
   290 qed
       
   291 
       
   292 end
       
   293 
       
   294 locale dense_linear_order = linorder_no_lb + linorder_no_ub +
       
   295   fixes between
       
   296   assumes between_less: "\<forall>x y. x \<sqsubset> y \<longrightarrow> x \<sqsubset> between x y \<and> between x y \<sqsubset> y"
       
   297      and  between_same: "\<forall>x. between x x = x"
       
   298 begin
       
   299 
       
   300 lemma rinf_U:
       
   301   assumes fU: "finite U"
       
   302   and lin_dense: "\<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P x
       
   303   \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P y )"
       
   304   and nmpiU: "\<forall>x. \<not> MP \<and> \<not>PP \<and> P x \<longrightarrow> (\<exists> u\<in> U. \<exists> u' \<in> U. u \<sqsubseteq> x \<and> x \<sqsubseteq> u')"
       
   305   and nmi: "\<not> MP"  and npi: "\<not> PP"  and ex: "\<exists> x.  P x"
       
   306   shows "\<exists> u\<in> U. \<exists> u' \<in> U. P (between u u')"
       
   307 proof-
       
   308   from ex obtain x where px: "P x" by blast
       
   309   from px nmi npi nmpiU have "\<exists> u\<in> U. \<exists> u' \<in> U. u \<sqsubseteq> x \<and> x \<sqsubseteq> u'" by auto
       
   310   then obtain u and u' where uU:"u\<in> U" and uU': "u' \<in> U" and ux:"u \<sqsubseteq> x" and xu':"x \<sqsubseteq> u'" by auto
       
   311   from uU have Une: "U \<noteq> {}" by auto
       
   312   let ?l = "Min U"
       
   313   let ?u = "Max U"
       
   314   have linM: "?l \<in> U" using fU Une by simp
       
   315   have uinM: "?u \<in> U" using fU Une by simp
       
   316   have lM: "\<forall> t\<in> U. ?l \<sqsubseteq> t" using Une fU by auto
       
   317   have Mu: "\<forall> t\<in> U. t \<sqsubseteq> ?u" using Une fU by auto
       
   318   have th:"?l \<sqsubseteq> u" using uU Une lM by auto
       
   319   from order_trans[OF th ux] have lx: "?l \<sqsubseteq> x" .
       
   320   have th: "u' \<sqsubseteq> ?u" using uU' Une Mu by simp
       
   321   from order_trans[OF xu' th] have xu: "x \<sqsubseteq> ?u" .
       
   322   from finite_set_intervals2[where P="P",OF px lx xu linM uinM fU lM Mu]
       
   323   have "(\<exists> s\<in> U. P s) \<or>
       
   324       (\<exists> t1\<in> U. \<exists> t2 \<in> U. (\<forall> y. t1 \<sqsubset> y \<and> y \<sqsubset> t2 \<longrightarrow> y \<notin> U) \<and> t1 \<sqsubset> x \<and> x \<sqsubset> t2 \<and> P x)" .
       
   325   moreover { fix u assume um: "u\<in>U" and pu: "P u"
       
   326     have "between u u = u" by (simp add: between_same)
       
   327     with um pu have "P (between u u)" by simp
       
   328     with um have ?thesis by blast}
       
   329   moreover{
       
   330     assume "\<exists> t1\<in> U. \<exists> t2 \<in> U. (\<forall> y. t1 \<sqsubset> y \<and> y \<sqsubset> t2 \<longrightarrow> y \<notin> U) \<and> t1 \<sqsubset> x \<and> x \<sqsubset> t2 \<and> P x"
       
   331       then obtain t1 and t2 where t1M: "t1 \<in> U" and t2M: "t2\<in> U"
       
   332         and noM: "\<forall> y. t1 \<sqsubset> y \<and> y \<sqsubset> t2 \<longrightarrow> y \<notin> U" and t1x: "t1 \<sqsubset> x" and xt2: "x \<sqsubset> t2" and px: "P x"
       
   333         by blast
       
   334       from less_trans[OF t1x xt2] have t1t2: "t1 \<sqsubset> t2" .
       
   335       let ?u = "between t1 t2"
       
   336       from between_less t1t2 have t1lu: "t1 \<sqsubset> ?u" and ut2: "?u \<sqsubset> t2" by auto
       
   337       from lin_dense[rule_format, OF] noM t1x xt2 px t1lu ut2 have "P ?u" by blast
       
   338       with t1M t2M have ?thesis by blast}
       
   339     ultimately show ?thesis by blast
       
   340   qed
       
   341 
       
   342 theorem fr_eq:
       
   343   assumes fU: "finite U"
       
   344   and lin_dense: "\<forall>x l u. (\<forall> t. l \<sqsubset> t \<and> t\<sqsubset> u \<longrightarrow> t \<notin> U) \<and> l\<sqsubset> x \<and> x \<sqsubset> u \<and> P x
       
   345    \<longrightarrow> (\<forall> y. l \<sqsubset> y \<and> y \<sqsubset> u \<longrightarrow> P y )"
       
   346   and nmibnd: "\<forall>x. \<not> MP \<and> P x \<longrightarrow> (\<exists> u\<in> U. u \<sqsubseteq> x)"
       
   347   and npibnd: "\<forall>x. \<not>PP \<and> P x \<longrightarrow> (\<exists> u\<in> U. x \<sqsubseteq> u)"
       
   348   and mi: "\<exists>z. \<forall>x. x \<sqsubset> z \<longrightarrow> (P x = MP)"  and pi: "\<exists>z. \<forall>x. z \<sqsubset> x \<longrightarrow> (P x = PP)"
       
   349   shows "(\<exists> x. P x) \<equiv> (MP \<or> PP \<or> (\<exists> u \<in> U. \<exists> u'\<in> U. P (between u u')))"
       
   350   (is "_ \<equiv> (_ \<or> _ \<or> ?F)" is "?E \<equiv> ?D")
       
   351 proof-
       
   352  {
       
   353    assume px: "\<exists> x. P x"
       
   354    have "MP \<or> PP \<or> (\<not> MP \<and> \<not> PP)" by blast
       
   355    moreover {assume "MP \<or> PP" hence "?D" by blast}
       
   356    moreover {assume nmi: "\<not> MP" and npi: "\<not> PP"
       
   357      from npmibnd[OF nmibnd npibnd]
       
   358      have nmpiU: "\<forall>x. \<not> MP \<and> \<not>PP \<and> P x \<longrightarrow> (\<exists> u\<in> U. \<exists> u' \<in> U. u \<sqsubseteq> x \<and> x \<sqsubseteq> u')" .
       
   359      from rinf_U[OF fU lin_dense nmpiU nmi npi px] have "?D" by blast}
       
   360    ultimately have "?D" by blast}
       
   361  moreover
       
   362  { assume "?D"
       
   363    moreover {assume m:"MP" from minf_ex[OF mi m] have "?E" .}
       
   364    moreover {assume p: "PP" from pinf_ex[OF pi p] have "?E" . }
       
   365    moreover {assume f:"?F" hence "?E" by blast}
       
   366    ultimately have "?E" by blast}
       
   367  ultimately have "?E = ?D" by blast thus "?E \<equiv> ?D" by simp
       
   368 qed
       
   369 
       
   370 lemmas minf_thms = minf_conj minf_disj minf_eq minf_neq minf_lt minf_le minf_gt minf_ge minf_P
       
   371 lemmas pinf_thms = pinf_conj pinf_disj pinf_eq pinf_neq pinf_lt pinf_le pinf_gt pinf_ge pinf_P
       
   372 
       
   373 lemmas nmi_thms = nmi_conj nmi_disj nmi_eq nmi_neq nmi_lt nmi_le nmi_gt nmi_ge nmi_P
       
   374 lemmas npi_thms = npi_conj npi_disj npi_eq npi_neq npi_lt npi_le npi_gt npi_ge npi_P
       
   375 lemmas lin_dense_thms = lin_dense_conj lin_dense_disj lin_dense_eq lin_dense_neq lin_dense_lt lin_dense_le lin_dense_gt lin_dense_ge lin_dense_P
       
   376 
       
   377 lemma ferrack_axiom: "dense_linear_order less_eq less between" by fact
       
   378 lemma atoms: includes meta_term_syntax
       
   379   shows "TERM (op \<sqsubset> :: 'a \<Rightarrow> _)" and "TERM (op \<sqsubseteq>)" and "TERM (op = :: 'a \<Rightarrow> _)" .
       
   380 
       
   381 declare ferrack_axiom [dlo minf: minf_thms pinf: pinf_thms
       
   382     nmi: nmi_thms npi: npi_thms lindense:
       
   383     lin_dense_thms qe: fr_eq atoms: atoms]
       
   384 
       
   385 declaration {*
       
   386 let
       
   387 fun generic_whatis phi =
       
   388  let
       
   389   val [lt, le] = map (Morphism.term phi)
       
   390    (ProofContext.read_term_pats @{typ "dummy"} @{context} ["op \<sqsubset>", "op \<sqsubseteq>"]) (* FIXME avoid read? *)
       
   391   val le = Morphism.term phi @{term "op \<sqsubseteq>"}
       
   392   fun h x t =
       
   393    case term_of t of
       
   394      Const("op =", _)$y$z => if term_of x aconv y then Ferrante_Rackoff_Data.Eq
       
   395                             else Ferrante_Rackoff_Data.Nox
       
   396    | @{term "Not"}$(Const("op =", _)$y$z) => if term_of x aconv y then Ferrante_Rackoff_Data.NEq
       
   397                             else Ferrante_Rackoff_Data.Nox
       
   398    | b$y$z => if Term.could_unify (b, lt) then
       
   399                  if term_of x aconv y then Ferrante_Rackoff_Data.Lt
       
   400                  else if term_of x aconv z then Ferrante_Rackoff_Data.Gt
       
   401                  else Ferrante_Rackoff_Data.Nox
       
   402              else if Term.could_unify (b, le) then
       
   403                  if term_of x aconv y then Ferrante_Rackoff_Data.Le
       
   404                  else if term_of x aconv z then Ferrante_Rackoff_Data.Ge
       
   405                  else Ferrante_Rackoff_Data.Nox
       
   406              else Ferrante_Rackoff_Data.Nox
       
   407    | _ => Ferrante_Rackoff_Data.Nox
       
   408  in h end
       
   409  val ss = K (HOL_ss addsimps [@{thm "not_less"}, @{thm "not_le"}])
       
   410 in
       
   411  Ferrante_Rackoff_Data.funs  @{thm "ferrack_axiom"}
       
   412   {isolate_conv = K (K (K Thm.reflexive)), whatis = generic_whatis, simpset = ss}
       
   413 end
       
   414 *}
       
   415 
       
   416 end
       
   417 
       
   418 use "Tools/Ferrante_Rackoff/ferrante_rackoff.ML"
       
   419 
       
   420 method_setup dlo = {*
       
   421   Method.ctxt_args (Method.SIMPLE_METHOD' o FerranteRackoff.dlo_tac)
       
   422 *} "Ferrante and Rackoff's algorithm for quantifier elimination in dense linear orders"
       
   423 
       
   424 end