src/ZF/Constructible/Reflection.thy
changeset 46823 57bf0cecb366
parent 36319 8feb2c4bef1a
child 58860 fee7cfa69c50
--- a/src/ZF/Constructible/Reflection.thy	Tue Mar 06 16:46:27 2012 +0000
+++ b/src/ZF/Constructible/Reflection.thy	Tue Mar 06 17:01:37 2012 +0000
@@ -6,26 +6,26 @@
 
 theory Reflection imports Normal begin
 
-lemma all_iff_not_ex_not: "(\<forall>x. P(x)) <-> (~ (\<exists>x. ~ P(x)))";
+lemma all_iff_not_ex_not: "(\<forall>x. P(x)) \<longleftrightarrow> (~ (\<exists>x. ~ P(x)))";
 by blast
 
-lemma ball_iff_not_bex_not: "(\<forall>x\<in>A. P(x)) <-> (~ (\<exists>x\<in>A. ~ P(x)))";
+lemma ball_iff_not_bex_not: "(\<forall>x\<in>A. P(x)) \<longleftrightarrow> (~ (\<exists>x\<in>A. ~ P(x)))";
 by blast
 
-text{*From the notes of A. S. Kechris, page 6, and from 
+text{*From the notes of A. S. Kechris, page 6, and from
       Andrzej Mostowski, \emph{Constructible Sets with Applications},
       North-Holland, 1969, page 23.*}
 
 
 subsection{*Basic Definitions*}
 
-text{*First part: the cumulative hierarchy defining the class @{text M}.  
+text{*First part: the cumulative hierarchy defining the class @{text M}.
 To avoid handling multiple arguments, we assume that @{text "Mset(l)"} is
 closed under ordered pairing provided @{text l} is limit.  Possibly this
-could be avoided: the induction hypothesis @{term Cl_reflects} 
+could be avoided: the induction hypothesis @{term Cl_reflects}
 (in locale @{text ex_reflection}) could be weakened to
-@{term "\<forall>y\<in>Mset(a). \<forall>z\<in>Mset(a). P(<y,z>) <-> Q(a,<y,z>)"}, removing most
-uses of @{term Pair_in_Mset}.  But there isn't much point in doing so, since 
+@{term "\<forall>y\<in>Mset(a). \<forall>z\<in>Mset(a). P(<y,z>) \<longleftrightarrow> Q(a,<y,z>)"}, removing most
+uses of @{term Pair_in_Mset}.  But there isn't much point in doing so, since
 ultimately the @{text ex_reflection} proof is packaged up using the
 predicate @{text Reflects}.
 *}
@@ -33,29 +33,29 @@
   fixes Mset and M and Reflects
   assumes Mset_mono_le : "mono_le_subset(Mset)"
       and Mset_cont    : "cont_Ord(Mset)"
-      and Pair_in_Mset : "[| x \<in> Mset(a); y \<in> Mset(a); Limit(a) |] 
+      and Pair_in_Mset : "[| x \<in> Mset(a); y \<in> Mset(a); Limit(a) |]
                           ==> <x,y> \<in> Mset(a)"
   defines "M(x) == \<exists>a. Ord(a) & x \<in> Mset(a)"
       and "Reflects(Cl,P,Q) == Closed_Unbounded(Cl) &
-                              (\<forall>a. Cl(a) --> (\<forall>x\<in>Mset(a). P(x) <-> Q(a,x)))"
+                              (\<forall>a. Cl(a) \<longrightarrow> (\<forall>x\<in>Mset(a). P(x) \<longleftrightarrow> Q(a,x)))"
   fixes F0 --{*ordinal for a specific value @{term y}*}
   fixes FF --{*sup over the whole level, @{term "y\<in>Mset(a)"}*}
   fixes ClEx --{*Reflecting ordinals for the formula @{term "\<exists>z. P"}*}
-  defines "F0(P,y) == \<mu> b. (\<exists>z. M(z) & P(<y,z>)) --> 
+  defines "F0(P,y) == \<mu> b. (\<exists>z. M(z) & P(<y,z>)) \<longrightarrow>
                                (\<exists>z\<in>Mset(b). P(<y,z>))"
       and "FF(P)   == \<lambda>a. \<Union>y\<in>Mset(a). F0(P,y)"
       and "ClEx(P,a) == Limit(a) & normalize(FF(P),a) = a"
 
-lemma (in reflection) Mset_mono: "i\<le>j ==> Mset(i) <= Mset(j)"
-apply (insert Mset_mono_le) 
-apply (simp add: mono_le_subset_def leI) 
+lemma (in reflection) Mset_mono: "i\<le>j ==> Mset(i) \<subseteq> Mset(j)"
+apply (insert Mset_mono_le)
+apply (simp add: mono_le_subset_def leI)
 done
 
 text{*Awkward: we need a version of @{text ClEx_def} as an equality
       at the level of classes, which do not really exist*}
 lemma (in reflection) ClEx_eq:
      "ClEx(P) == \<lambda>a. Limit(a) & normalize(FF(P),a) = a"
-by (simp add: ClEx_def [symmetric]) 
+by (simp add: ClEx_def [symmetric])
 
 
 subsection{*Easy Cases of the Reflection Theorem*}
@@ -66,33 +66,33 @@
 
 theorem (in reflection) Not_reflection [intro]:
      "Reflects(Cl,P,Q) ==> Reflects(Cl, \<lambda>x. ~P(x), \<lambda>a x. ~Q(a,x))"
-by (simp add: Reflects_def) 
+by (simp add: Reflects_def)
 
 theorem (in reflection) And_reflection [intro]:
-     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |] 
-      ==> Reflects(\<lambda>a. Cl(a) & C'(a), \<lambda>x. P(x) & P'(x), 
+     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |]
+      ==> Reflects(\<lambda>a. Cl(a) & C'(a), \<lambda>x. P(x) & P'(x),
                                       \<lambda>a x. Q(a,x) & Q'(a,x))"
 by (simp add: Reflects_def Closed_Unbounded_Int, blast)
 
 theorem (in reflection) Or_reflection [intro]:
-     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |] 
-      ==> Reflects(\<lambda>a. Cl(a) & C'(a), \<lambda>x. P(x) | P'(x), 
+     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |]
+      ==> Reflects(\<lambda>a. Cl(a) & C'(a), \<lambda>x. P(x) | P'(x),
                                       \<lambda>a x. Q(a,x) | Q'(a,x))"
 by (simp add: Reflects_def Closed_Unbounded_Int, blast)
 
 theorem (in reflection) Imp_reflection [intro]:
-     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |] 
-      ==> Reflects(\<lambda>a. Cl(a) & C'(a), 
-                   \<lambda>x. P(x) --> P'(x), 
-                   \<lambda>a x. Q(a,x) --> Q'(a,x))"
+     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |]
+      ==> Reflects(\<lambda>a. Cl(a) & C'(a),
+                   \<lambda>x. P(x) \<longrightarrow> P'(x),
+                   \<lambda>a x. Q(a,x) \<longrightarrow> Q'(a,x))"
 by (simp add: Reflects_def Closed_Unbounded_Int, blast)
 
 theorem (in reflection) Iff_reflection [intro]:
-     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |] 
-      ==> Reflects(\<lambda>a. Cl(a) & C'(a), 
-                   \<lambda>x. P(x) <-> P'(x), 
-                   \<lambda>a x. Q(a,x) <-> Q'(a,x))"
-by (simp add: Reflects_def Closed_Unbounded_Int, blast) 
+     "[| Reflects(Cl,P,Q); Reflects(C',P',Q') |]
+      ==> Reflects(\<lambda>a. Cl(a) & C'(a),
+                   \<lambda>x. P(x) \<longleftrightarrow> P'(x),
+                   \<lambda>a x. Q(a,x) \<longleftrightarrow> Q'(a,x))"
+by (simp add: Reflects_def Closed_Unbounded_Int, blast)
 
 subsection{*Reflection for Existential Quantifiers*}
 
@@ -115,20 +115,20 @@
 apply (simp add: cont_Ord_def FF_def, blast)
 done
 
-text{*Recall that @{term F0} depends upon @{term "y\<in>Mset(a)"}, 
+text{*Recall that @{term F0} depends upon @{term "y\<in>Mset(a)"},
 while @{term FF} depends only upon @{term a}. *}
 lemma (in reflection) FF_works:
      "[| M(z); y\<in>Mset(a); P(<y,z>); Ord(a) |] ==> \<exists>z\<in>Mset(FF(P,a)). P(<y,z>)"
 apply (simp add: FF_def)
-apply (simp_all add: cont_Ord_Union [of concl: Mset] 
+apply (simp_all add: cont_Ord_Union [of concl: Mset]
                      Mset_cont Mset_mono_le not_emptyI Ord_F0)
-apply (blast intro: F0_works)  
+apply (blast intro: F0_works)
 done
 
 lemma (in reflection) FFN_works:
-     "[| M(z); y\<in>Mset(a); P(<y,z>); Ord(a) |] 
+     "[| M(z); y\<in>Mset(a); P(<y,z>); Ord(a) |]
       ==> \<exists>z\<in>Mset(normalize(FF(P),a)). P(<y,z>)"
-apply (drule FF_works [of concl: P], assumption+) 
+apply (drule FF_works [of concl: P], assumption+)
 apply (blast intro: cont_Ord_FF le_normalize [THEN Mset_mono, THEN subsetD])
 done
 
@@ -139,20 +139,20 @@
   fixes P  --"the original formula"
   fixes Q  --"the reflected formula"
   fixes Cl --"the class of reflecting ordinals"
-  assumes Cl_reflects: "[| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) <-> Q(a,x)"
+  assumes Cl_reflects: "[| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) \<longleftrightarrow> Q(a,x)"
 
 lemma (in ex_reflection) ClEx_downward:
-     "[| M(z); y\<in>Mset(a); P(<y,z>); Cl(a); ClEx(P,a) |] 
+     "[| M(z); y\<in>Mset(a); P(<y,z>); Cl(a); ClEx(P,a) |]
       ==> \<exists>z\<in>Mset(a). Q(a,<y,z>)"
-apply (simp add: ClEx_def, clarify) 
-apply (frule Limit_is_Ord) 
-apply (frule FFN_works [of concl: P], assumption+) 
-apply (drule Cl_reflects, assumption+) 
+apply (simp add: ClEx_def, clarify)
+apply (frule Limit_is_Ord)
+apply (frule FFN_works [of concl: P], assumption+)
+apply (drule Cl_reflects, assumption+)
 apply (auto simp add: Limit_is_Ord Pair_in_Mset)
 done
 
 lemma (in ex_reflection) ClEx_upward:
-     "[| z\<in>Mset(a); y\<in>Mset(a); Q(a,<y,z>); Cl(a); ClEx(P,a) |] 
+     "[| z\<in>Mset(a); y\<in>Mset(a); Q(a,<y,z>); Cl(a); ClEx(P,a) |]
       ==> \<exists>z. M(z) & P(<y,z>)"
 apply (simp add: ClEx_def M_def)
 apply (blast dest: Cl_reflects
@@ -161,9 +161,9 @@
 
 text{*Class @{text ClEx} indeed consists of reflecting ordinals...*}
 lemma (in ex_reflection) ZF_ClEx_iff:
-     "[| y\<in>Mset(a); Cl(a); ClEx(P,a) |] 
-      ==> (\<exists>z. M(z) & P(<y,z>)) <-> (\<exists>z\<in>Mset(a). Q(a,<y,z>))"
-by (blast intro: dest: ClEx_downward ClEx_upward) 
+     "[| y\<in>Mset(a); Cl(a); ClEx(P,a) |]
+      ==> (\<exists>z. M(z) & P(<y,z>)) \<longleftrightarrow> (\<exists>z\<in>Mset(a). Q(a,<y,z>))"
+by (blast intro: dest: ClEx_downward ClEx_upward)
 
 text{*...and it is closed and unbounded*}
 lemma (in ex_reflection) ZF_Closed_Unbounded_ClEx:
@@ -178,8 +178,8 @@
 text{*Class @{text ClEx} indeed consists of reflecting ordinals...*}
 lemma (in reflection) ClEx_iff:
      "[| y\<in>Mset(a); Cl(a); ClEx(P,a);
-        !!a. [| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) <-> Q(a,x) |] 
-      ==> (\<exists>z. M(z) & P(<y,z>)) <-> (\<exists>z\<in>Mset(a). Q(a,<y,z>))"
+        !!a. [| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) \<longleftrightarrow> Q(a,x) |]
+      ==> (\<exists>z. M(z) & P(<y,z>)) \<longleftrightarrow> (\<exists>z\<in>Mset(a). Q(a,<y,z>))"
 apply (unfold ClEx_def FF_def F0_def M_def)
 apply (rule ex_reflection.ZF_ClEx_iff
   [OF ex_reflection.intro, OF reflection.intro ex_reflection_axioms.intro,
@@ -195,9 +195,9 @@
 *)
 
 lemma (in reflection) Closed_Unbounded_ClEx:
-     "(!!a. [| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) <-> Q(a,x))
+     "(!!a. [| Cl(a); Ord(a) |] ==> \<forall>x\<in>Mset(a). P(x) \<longleftrightarrow> Q(a,x))
       ==> Closed_Unbounded(ClEx(P))"
-apply (unfold ClEx_eq FF_def F0_def M_def) 
+apply (unfold ClEx_eq FF_def F0_def M_def)
 apply (rule ex_reflection.ZF_Closed_Unbounded_ClEx [of Mset _ _ Cl])
 apply (rule ex_reflection.intro, rule reflection_axioms)
 apply (blast intro: ex_reflection_axioms.intro)
@@ -206,58 +206,58 @@
 subsection{*Packaging the Quantifier Reflection Rules*}
 
 lemma (in reflection) Ex_reflection_0:
-     "Reflects(Cl,P0,Q0) 
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(P0,a), 
-                   \<lambda>x. \<exists>z. M(z) & P0(<x,z>), 
-                   \<lambda>a x. \<exists>z\<in>Mset(a). Q0(a,<x,z>))" 
-apply (simp add: Reflects_def) 
+     "Reflects(Cl,P0,Q0)
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(P0,a),
+                   \<lambda>x. \<exists>z. M(z) & P0(<x,z>),
+                   \<lambda>a x. \<exists>z\<in>Mset(a). Q0(a,<x,z>))"
+apply (simp add: Reflects_def)
 apply (intro conjI Closed_Unbounded_Int)
-  apply blast 
- apply (rule Closed_Unbounded_ClEx [of Cl P0 Q0], blast, clarify) 
-apply (rule_tac Cl=Cl in  ClEx_iff, assumption+, blast) 
+  apply blast
+ apply (rule Closed_Unbounded_ClEx [of Cl P0 Q0], blast, clarify)
+apply (rule_tac Cl=Cl in  ClEx_iff, assumption+, blast)
 done
 
 lemma (in reflection) All_reflection_0:
-     "Reflects(Cl,P0,Q0) 
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x.~P0(x), a), 
-                   \<lambda>x. \<forall>z. M(z) --> P0(<x,z>), 
-                   \<lambda>a x. \<forall>z\<in>Mset(a). Q0(a,<x,z>))" 
-apply (simp only: all_iff_not_ex_not ball_iff_not_bex_not) 
-apply (rule Not_reflection, drule Not_reflection, simp) 
+     "Reflects(Cl,P0,Q0)
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x.~P0(x), a),
+                   \<lambda>x. \<forall>z. M(z) \<longrightarrow> P0(<x,z>),
+                   \<lambda>a x. \<forall>z\<in>Mset(a). Q0(a,<x,z>))"
+apply (simp only: all_iff_not_ex_not ball_iff_not_bex_not)
+apply (rule Not_reflection, drule Not_reflection, simp)
 apply (erule Ex_reflection_0)
 done
 
 theorem (in reflection) Ex_reflection [intro]:
-     "Reflects(Cl, \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x))) 
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. P(fst(x),snd(x)), a), 
-                   \<lambda>x. \<exists>z. M(z) & P(x,z), 
+     "Reflects(Cl, \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x)))
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. P(fst(x),snd(x)), a),
+                   \<lambda>x. \<exists>z. M(z) & P(x,z),
                    \<lambda>a x. \<exists>z\<in>Mset(a). Q(a,x,z))"
-by (rule Ex_reflection_0 [of _ " \<lambda>x. P(fst(x),snd(x))" 
+by (rule Ex_reflection_0 [of _ " \<lambda>x. P(fst(x),snd(x))"
                                "\<lambda>a x. Q(a,fst(x),snd(x))", simplified])
 
 theorem (in reflection) All_reflection [intro]:
      "Reflects(Cl,  \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x)))
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. ~P(fst(x),snd(x)), a), 
-                   \<lambda>x. \<forall>z. M(z) --> P(x,z), 
-                   \<lambda>a x. \<forall>z\<in>Mset(a). Q(a,x,z))" 
-by (rule All_reflection_0 [of _ "\<lambda>x. P(fst(x),snd(x))" 
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. ~P(fst(x),snd(x)), a),
+                   \<lambda>x. \<forall>z. M(z) \<longrightarrow> P(x,z),
+                   \<lambda>a x. \<forall>z\<in>Mset(a). Q(a,x,z))"
+by (rule All_reflection_0 [of _ "\<lambda>x. P(fst(x),snd(x))"
                                 "\<lambda>a x. Q(a,fst(x),snd(x))", simplified])
 
 text{*And again, this time using class-bounded quantifiers*}
 
 theorem (in reflection) Rex_reflection [intro]:
-     "Reflects(Cl, \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x))) 
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. P(fst(x),snd(x)), a), 
-                   \<lambda>x. \<exists>z[M]. P(x,z), 
+     "Reflects(Cl, \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x)))
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. P(fst(x),snd(x)), a),
+                   \<lambda>x. \<exists>z[M]. P(x,z),
                    \<lambda>a x. \<exists>z\<in>Mset(a). Q(a,x,z))"
-by (unfold rex_def, blast) 
+by (unfold rex_def, blast)
 
 theorem (in reflection) Rall_reflection [intro]:
      "Reflects(Cl,  \<lambda>x. P(fst(x),snd(x)), \<lambda>a x. Q(a,fst(x),snd(x)))
-      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. ~P(fst(x),snd(x)), a), 
-                   \<lambda>x. \<forall>z[M]. P(x,z), 
-                   \<lambda>a x. \<forall>z\<in>Mset(a). Q(a,x,z))" 
-by (unfold rall_def, blast) 
+      ==> Reflects(\<lambda>a. Cl(a) & ClEx(\<lambda>x. ~P(fst(x),snd(x)), a),
+                   \<lambda>x. \<forall>z[M]. P(x,z),
+                   \<lambda>a x. \<forall>z\<in>Mset(a). Q(a,x,z))"
+by (unfold rall_def, blast)
 
 
 text{*No point considering bounded quantifiers, where reflection is trivial.*}
@@ -266,62 +266,62 @@
 subsection{*Simple Examples of Reflection*}
 
 text{*Example 1: reflecting a simple formula.  The reflecting class is first
-given as the variable @{text ?Cl} and later retrieved from the final 
+given as the variable @{text ?Cl} and later retrieved from the final
 proof state.*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
-               \<lambda>x. \<exists>y. M(y) & x \<in> y, 
+               \<lambda>x. \<exists>y. M(y) & x \<in> y,
                \<lambda>a x. \<exists>y\<in>Mset(a). x \<in> y)"
 by fast
 
 text{*Problem here: there needs to be a conjunction (class intersection)
 in the class of reflecting ordinals.  The @{term "Ord(a)"} is redundant,
 though harmless.*}
-lemma (in reflection) 
-     "Reflects(\<lambda>a. Ord(a) & ClEx(\<lambda>x. fst(x) \<in> snd(x), a),   
-               \<lambda>x. \<exists>y. M(y) & x \<in> y, 
-               \<lambda>a x. \<exists>y\<in>Mset(a). x \<in> y)" 
+lemma (in reflection)
+     "Reflects(\<lambda>a. Ord(a) & ClEx(\<lambda>x. fst(x) \<in> snd(x), a),
+               \<lambda>x. \<exists>y. M(y) & x \<in> y,
+               \<lambda>a x. \<exists>y\<in>Mset(a). x \<in> y)"
 by fast
 
 
 text{*Example 2*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
-               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) --> z \<subseteq> x --> z \<in> y), 
-               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x --> z \<in> y)" 
+               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) \<longrightarrow> z \<subseteq> x \<longrightarrow> z \<in> y),
+               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x \<longrightarrow> z \<in> y)"
 by fast
 
 text{*Example 2'.  We give the reflecting class explicitly. *}
-lemma (in reflection) 
+lemma (in reflection)
   "Reflects
     (\<lambda>a. (Ord(a) &
-          ClEx(\<lambda>x. ~ (snd(x) \<subseteq> fst(fst(x)) --> snd(x) \<in> snd(fst(x))), a)) &
-          ClEx(\<lambda>x. \<forall>z. M(z) --> z \<subseteq> fst(x) --> z \<in> snd(x), a),
-            \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) --> z \<subseteq> x --> z \<in> y), 
-            \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x --> z \<in> y)" 
+          ClEx(\<lambda>x. ~ (snd(x) \<subseteq> fst(fst(x)) \<longrightarrow> snd(x) \<in> snd(fst(x))), a)) &
+          ClEx(\<lambda>x. \<forall>z. M(z) \<longrightarrow> z \<subseteq> fst(x) \<longrightarrow> z \<in> snd(x), a),
+            \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) \<longrightarrow> z \<subseteq> x \<longrightarrow> z \<in> y),
+            \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x \<longrightarrow> z \<in> y)"
 by fast
 
 text{*Example 2''.  We expand the subset relation.*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
   "Reflects(?Cl,
-        \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) --> (\<forall>w. M(w) --> w\<in>z --> w\<in>x) --> z\<in>y),
-        \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). (\<forall>w\<in>Mset(a). w\<in>z --> w\<in>x) --> z\<in>y)"
+        \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) \<longrightarrow> (\<forall>w. M(w) \<longrightarrow> w\<in>z \<longrightarrow> w\<in>x) \<longrightarrow> z\<in>y),
+        \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). (\<forall>w\<in>Mset(a). w\<in>z \<longrightarrow> w\<in>x) \<longrightarrow> z\<in>y)"
 by fast
 
 text{*Example 2'''.  Single-step version, to reveal the reflecting class.*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
-               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) --> z \<subseteq> x --> z \<in> y), 
-               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x --> z \<in> y)" 
-apply (rule Ex_reflection) 
+               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) \<longrightarrow> z \<subseteq> x \<longrightarrow> z \<in> y),
+               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<subseteq> x \<longrightarrow> z \<in> y)"
+apply (rule Ex_reflection)
 txt{*
 @{goals[display,indent=0,margin=60]}
 *}
-apply (rule All_reflection) 
+apply (rule All_reflection)
 txt{*
 @{goals[display,indent=0,margin=60]}
 *}
-apply (rule Triv_reflection) 
+apply (rule Triv_reflection)
 txt{*
 @{goals[display,indent=0,margin=60]}
 *}
@@ -329,21 +329,21 @@
 
 text{*Example 3.  Warning: the following examples make sense only
 if @{term P} is quantifier-free, since it is not being relativized.*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
-               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) --> z \<in> y <-> z \<in> x & P(z)), 
-               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<in> y <-> z \<in> x & P(z))"
+               \<lambda>x. \<exists>y. M(y) & (\<forall>z. M(z) \<longrightarrow> z \<in> y \<longleftrightarrow> z \<in> x & P(z)),
+               \<lambda>a x. \<exists>y\<in>Mset(a). \<forall>z\<in>Mset(a). z \<in> y \<longleftrightarrow> z \<in> x & P(z))"
 by fast
 
 text{*Example 3'*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
                \<lambda>x. \<exists>y. M(y) & y = Collect(x,P),
                \<lambda>a x. \<exists>y\<in>Mset(a). y = Collect(x,P))";
 by fast
 
 text{*Example 3''*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
                \<lambda>x. \<exists>y. M(y) & y = Replace(x,P),
                \<lambda>a x. \<exists>y\<in>Mset(a). y = Replace(x,P))";
@@ -351,10 +351,10 @@
 
 text{*Example 4: Axiom of Choice.  Possibly wrong, since @{text \<Pi>} needs
 to be relativized.*}
-schematic_lemma (in reflection) 
+schematic_lemma (in reflection)
      "Reflects(?Cl,
-               \<lambda>A. 0\<notin>A --> (\<exists>f. M(f) & f \<in> (\<Pi> X \<in> A. X)),
-               \<lambda>a A. 0\<notin>A --> (\<exists>f\<in>Mset(a). f \<in> (\<Pi> X \<in> A. X)))"
+               \<lambda>A. 0\<notin>A \<longrightarrow> (\<exists>f. M(f) & f \<in> (\<Pi> X \<in> A. X)),
+               \<lambda>a A. 0\<notin>A \<longrightarrow> (\<exists>f\<in>Mset(a). f \<in> (\<Pi> X \<in> A. X)))"
 by fast
 
 end