src/ZF/ex/misc.thy
changeset 76214 0c18df79b1c8
parent 76213 e44d86131648
child 76215 a642599ffdea
equal deleted inserted replaced
76213:e44d86131648 76214:0c18df79b1c8
    34 lemma "b\<noteq>c \<Longrightarrow> <a,b> \<inter> <a,c> = <a,a>"
    34 lemma "b\<noteq>c \<Longrightarrow> <a,b> \<inter> <a,c> = <a,a>"
    35 by (simp add: Pair_def Int_cons_left Int_cons_right doubleton_eq_iff, blast)
    35 by (simp add: Pair_def Int_cons_left Int_cons_right doubleton_eq_iff, blast)
    36 
    36 
    37 text\<open>These two are cited in Benzmueller and Kohlhase's system description of
    37 text\<open>These two are cited in Benzmueller and Kohlhase's system description of
    38  LEO, CADE-15, 1998 (page 139-143) as theorems LEO could not prove.\<close>
    38  LEO, CADE-15, 1998 (page 139-143) as theorems LEO could not prove.\<close>
    39 lemma "(X = Y \<union> Z) \<longleftrightarrow> (Y \<subseteq> X & Z \<subseteq> X & (\<forall>V. Y \<subseteq> V & Z \<subseteq> V \<longrightarrow> X \<subseteq> V))"
    39 lemma "(X = Y \<union> Z) \<longleftrightarrow> (Y \<subseteq> X \<and> Z \<subseteq> X \<and> (\<forall>V. Y \<subseteq> V \<and> Z \<subseteq> V \<longrightarrow> X \<subseteq> V))"
    40 by (blast intro!: equalityI)
    40 by (blast intro!: equalityI)
    41 
    41 
    42 text\<open>the dual of the previous one\<close>
    42 text\<open>the dual of the previous one\<close>
    43 lemma "(X = Y \<inter> Z) \<longleftrightarrow> (X \<subseteq> Y & X \<subseteq> Z & (\<forall>V. V \<subseteq> Y & V \<subseteq> Z \<longrightarrow> V \<subseteq> X))"
    43 lemma "(X = Y \<inter> Z) \<longleftrightarrow> (X \<subseteq> Y \<and> X \<subseteq> Z \<and> (\<forall>V. V \<subseteq> Y \<and> V \<subseteq> Z \<longrightarrow> V \<subseteq> X))"
    44 by (blast intro!: equalityI)
    44 by (blast intro!: equalityI)
    45 
    45 
    46 text\<open>trivial example of term synthesis: apparently hard for some provers!\<close>
    46 text\<open>trivial example of term synthesis: apparently hard for some provers!\<close>
    47 schematic_goal "a \<noteq> b \<Longrightarrow> a:?X & b \<notin> ?X"
    47 schematic_goal "a \<noteq> b \<Longrightarrow> a:?X \<and> b \<notin> ?X"
    48 by blast
    48 by blast
    49 
    49 
    50 text\<open>Nice blast benchmark.  Proved in 0.3s; old tactics can't manage it!\<close>
    50 text\<open>Nice blast benchmark.  Proved in 0.3s; old tactics can't manage it!\<close>
    51 lemma "\<forall>x \<in> S. \<forall>y \<in> S. x \<subseteq> y \<Longrightarrow> \<exists>z. S \<subseteq> {z}"
    51 lemma "\<forall>x \<in> S. \<forall>y \<in> S. x \<subseteq> y \<Longrightarrow> \<exists>z. S \<subseteq> {z}"
    52 by blast
    52 by blast
    61  Ellis Horwood, 53-100 (1979). *)
    61  Ellis Horwood, 53-100 (1979). *)
    62 lemma "(\<forall>F. {x} \<in> F \<longrightarrow> {y} \<in> F) \<longrightarrow> (\<forall>A. x \<in> A \<longrightarrow> y \<in> A)"
    62 lemma "(\<forall>F. {x} \<in> F \<longrightarrow> {y} \<in> F) \<longrightarrow> (\<forall>A. x \<in> A \<longrightarrow> y \<in> A)"
    63 by best
    63 by best
    64 
    64 
    65 text\<open>A characterization of functions suggested by Tobias Nipkow\<close>
    65 text\<open>A characterization of functions suggested by Tobias Nipkow\<close>
    66 lemma "r \<in> domain(r)->B  \<longleftrightarrow>  r \<subseteq> domain(r)*B & (\<forall>X. r `` (r -`` X) \<subseteq> X)"
    66 lemma "r \<in> domain(r)->B  \<longleftrightarrow>  r \<subseteq> domain(r)*B \<and> (\<forall>X. r `` (r -`` X) \<subseteq> X)"
    67 by (unfold Pi_def function_def, best)
    67 by (unfold Pi_def function_def, best)
    68 
    68 
    69 
    69 
    70 subsection\<open>Composition of homomorphisms is a Homomorphism\<close>
    70 subsection\<open>Composition of homomorphisms is a Homomorphism\<close>
    71 
    71 
    78 declare comp_fun [simp] SigmaI [simp] apply_funtype [simp]
    78 declare comp_fun [simp] SigmaI [simp] apply_funtype [simp]
    79 
    79 
    80 (*Force helps prove conditions of rewrites such as comp_fun_apply, since
    80 (*Force helps prove conditions of rewrites such as comp_fun_apply, since
    81   rewriting does not instantiate Vars.*)
    81   rewriting does not instantiate Vars.*)
    82 lemma "(\<forall>A f B g. hom(A,f,B,g) =  
    82 lemma "(\<forall>A f B g. hom(A,f,B,g) =  
    83            {H \<in> A->B. f \<in> A*A->A & g \<in> B*B->B &  
    83            {H \<in> A->B. f \<in> A*A->A \<and> g \<in> B*B->B \<and>  
    84                      (\<forall>x \<in> A. \<forall>y \<in> A. H`(f`<x,y>) = g`<H`x,H`y>)}) \<longrightarrow>  
    84                      (\<forall>x \<in> A. \<forall>y \<in> A. H`(f`<x,y>) = g`<H`x,H`y>)}) \<longrightarrow>  
    85        J \<in> hom(A,f,B,g) & K \<in> hom(B,g,C,h) \<longrightarrow>   
    85        J \<in> hom(A,f,B,g) \<and> K \<in> hom(B,g,C,h) \<longrightarrow>   
    86        (K O J) \<in> hom(A,f,C,h)"
    86        (K O J) \<in> hom(A,f,C,h)"
    87 by force
    87 by force
    88 
    88 
    89 text\<open>Another version, with meta-level rewriting\<close>
    89 text\<open>Another version, with meta-level rewriting\<close>
    90 lemma "(\<And>A f B g. hom(A,f,B,g) \<equiv>  
    90 lemma "(\<And>A f B g. hom(A,f,B,g) \<equiv>  
    91            {H \<in> A->B. f \<in> A*A->A & g \<in> B*B->B &  
    91            {H \<in> A->B. f \<in> A*A->A \<and> g \<in> B*B->B \<and>  
    92                      (\<forall>x \<in> A. \<forall>y \<in> A. H`(f`<x,y>) = g`<H`x,H`y>)}) 
    92                      (\<forall>x \<in> A. \<forall>y \<in> A. H`(f`<x,y>) = g`<H`x,H`y>)}) 
    93        \<Longrightarrow> J \<in> hom(A,f,B,g) & K \<in> hom(B,g,C,h) \<longrightarrow> (K O J) \<in> hom(A,f,C,h)"
    93        \<Longrightarrow> J \<in> hom(A,f,B,g) \<and> K \<in> hom(B,g,C,h) \<longrightarrow> (K O J) \<in> hom(A,f,C,h)"
    94 by force
    94 by force
    95 
    95 
    96 
    96 
    97 subsection\<open>Pastre's Examples\<close>
    97 subsection\<open>Pastre's Examples\<close>
    98 
    98