diff -r df64653779e1 -r 6d02bb8b5fe1 src/Doc/Tutorial/Protocol/Message.thy
--- a/src/Doc/Tutorial/Protocol/Message.thy	Wed Dec 30 20:11:19 2015 +0100
+++ b/src/Doc/Tutorial/Protocol/Message.thy	Wed Dec 30 20:12:26 2015 +0100
@@ -79,16 +79,12 @@
 *}
 
 (*<*)
-text{*Concrete syntax: messages appear as {|A,B,NA|}, etc...*}
+text{*Concrete syntax: messages appear as \<open>\<lbrace>A,B,NA\<rbrace>\<close>, etc...*}
 syntax
-  "_MTuple"      :: "['a, args] => 'a * 'b"       ("(2{|_,/ _|})")
-
-syntax (xsymbols)
   "_MTuple"      :: "['a, args] => 'a * 'b"       ("(2\<lbrace>_,/ _\<rbrace>)")
-
 translations
-  "{|x, y, z|}"   == "{|x, {|y, z|}|}"
-  "{|x, y|}"      == "CONST MPair x y"
+  "\<lbrace>x, y, z\<rbrace>"   == "\<lbrace>x, \<lbrace>y, z\<rbrace>\<rbrace>"
+  "\<lbrace>x, y\<rbrace>"      == "CONST MPair x y"
 
 
 definition keysFor :: "msg set => key set" where
@@ -103,8 +99,8 @@
   for H :: "msg set"
   where
     Inj [intro]:               "X \<in> H ==> X \<in> parts H"
-  | Fst:         "{|X,Y|}   \<in> parts H ==> X \<in> parts H"
-  | Snd:         "{|X,Y|}   \<in> parts H ==> Y \<in> parts H"
+  | Fst:         "\<lbrace>X,Y\<rbrace>   \<in> parts H ==> X \<in> parts H"
+  | Snd:         "\<lbrace>X,Y\<rbrace>   \<in> parts H ==> Y \<in> parts H"
   | Body:        "Crypt K X \<in> parts H ==> X \<in> parts H"
 
 
@@ -159,7 +155,7 @@
 lemma keysFor_insert_Key [simp]: "keysFor (insert (Key K) H) = keysFor H"
 by (unfold keysFor_def, auto)
 
-lemma keysFor_insert_MPair [simp]: "keysFor (insert {|X,Y|} H) = keysFor H"
+lemma keysFor_insert_MPair [simp]: "keysFor (insert \<lbrace>X,Y\<rbrace> H) = keysFor H"
 by (unfold keysFor_def, auto)
 
 lemma keysFor_insert_Crypt [simp]: 
@@ -176,7 +172,7 @@
 subsection{*Inductive relation "parts"*}
 
 lemma MPair_parts:
-     "[| {|X,Y|} \<in> parts H;        
+     "[| \<lbrace>X,Y\<rbrace> \<in> parts H;        
          [| X \<in> parts H; Y \<in> parts H |] ==> P |] ==> P"
 by (blast dest: parts.Fst parts.Snd) 
 
@@ -313,8 +309,8 @@
 done
 
 lemma parts_insert_MPair [simp]:
-     "parts (insert {|X,Y|} H) =  
-          insert {|X,Y|} (parts (insert X (insert Y H)))"
+     "parts (insert \<lbrace>X,Y\<rbrace> H) =  
+          insert \<lbrace>X,Y\<rbrace> (parts (insert X (insert Y H)))"
 apply (rule equalityI)
 apply (rule subsetI)
 apply (erule parts.induct, auto)
@@ -375,7 +371,7 @@
 
 text{*Making it safe speeds up proofs*}
 lemma MPair_analz [elim!]:
-     "[| {|X,Y|} \<in> analz H;        
+     "[| \<lbrace>X,Y\<rbrace> \<in> analz H;        
              [| X \<in> analz H; Y \<in> analz H |] ==> P   
           |] ==> P"
 by (blast dest: analz.Fst analz.Snd)
@@ -447,8 +443,8 @@
 done
 
 lemma analz_insert_MPair [simp]:
-     "analz (insert {|X,Y|} H) =  
-          insert {|X,Y|} (analz (insert X (insert Y H)))"
+     "analz (insert \<lbrace>X,Y\<rbrace> H) =  
+          insert \<lbrace>X,Y\<rbrace> (analz (insert X (insert Y H)))"
 apply (rule equalityI)
 apply (rule subsetI)
 apply (erule analz.induct, auto)
@@ -565,7 +561,7 @@
 
 text{*If there are no pairs or encryptions then analz does nothing*}
 lemma analz_trivial:
-     "[| \<forall>X Y. {|X,Y|} \<notin> H;  \<forall>X K. Crypt K X \<notin> H |] ==> analz H = H"
+     "[| \<forall>X Y. \<lbrace>X,Y\<rbrace> \<notin> H;  \<forall>X K. Crypt K X \<notin> H |] ==> analz H = H"
 apply safe
 apply (erule analz.induct, blast+)
 done
@@ -606,7 +602,7 @@
   by (auto, erule synth.induct, auto)  
 
 inductive_cases Key_synth   [elim!]: "Key K \<in> synth H"
-inductive_cases MPair_synth [elim!]: "{|X,Y|} \<in> synth H"
+inductive_cases MPair_synth [elim!]: "\<lbrace>X,Y\<rbrace> \<in> synth H"
 inductive_cases Crypt_synth [elim!]: "Crypt K X \<in> synth H"
 
 lemma analz_synth_Un [simp]: "analz (synth G \<union> H) = analz (G \<union> H) \<union> synth G"
@@ -769,7 +765,7 @@
 text{*Without this equation, other rules for synth and analz would yield
   redundant cases*}
 lemma MPair_synth_analz [iff]:
-     "({|X,Y|} \<in> synth (analz H)) =  
+     "(\<lbrace>X,Y\<rbrace> \<in> synth (analz H)) =  
       (X \<in> synth (analz H) & Y \<in> synth (analz H))"
 by blast