constant =?= no longer exists (cf. 8c09e1fa24a7);

--- a/doc-src/IsarRef/Thy/Inner_Syntax.thy	Thu Apr 07 20:56:48 2011 +0200
+++ b/doc-src/IsarRef/Thy/Inner_Syntax.thy	Thu Apr 07 21:23:57 2011 +0200
@@ -496,7 +496,6 @@
 
   @{syntax_def (inner) prop} & = & @{verbatim "("} @{text prop} @{verbatim ")"} \\
     & @{text "|"} & @{text "prop\<^sup>(\<^sup>4\<^sup>)"} @{verbatim "::"} @{text type} & @{text "(3)"} \\
-    & @{text "|"} & @{text "any\<^sup>(\<^sup>3\<^sup>)"} @{verbatim "=?="} @{text "any\<^sup>(\<^sup>2\<^sup>)"} & @{text "(2)"} \\
     & @{text "|"} & @{text "any\<^sup>(\<^sup>3\<^sup>)"} @{verbatim "=="} @{text "any\<^sup>(\<^sup>2\<^sup>)"} & @{text "(2)"} \\
     & @{text "|"} & @{text "any\<^sup>(\<^sup>3\<^sup>)"} @{text "\<equiv>"} @{text "any\<^sup>(\<^sup>2\<^sup>)"} & @{text "(2)"} \\
     & @{text "|"} & @{text "prop\<^sup>(\<^sup>3\<^sup>)"} @{verbatim "&&&"} @{text "prop\<^sup>(\<^sup>2\<^sup>)"} & @{text "(2)"} \\

--- a/doc-src/IsarRef/Thy/document/Inner_Syntax.tex	Thu Apr 07 20:56:48 2011 +0200
+++ b/doc-src/IsarRef/Thy/document/Inner_Syntax.tex	Thu Apr 07 21:23:57 2011 +0200
@@ -522,7 +522,6 @@
 
   \indexdef{inner}{syntax}{prop}\hypertarget{syntax.inner.prop}{\hyperlink{syntax.inner.prop}{\mbox{\isa{prop}}}} & = & \verb|(| \isa{prop} \verb|)| \\
     & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}prop\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{4}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \verb|::| \isa{type} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{28}{\isacharparenleft}}{\isadigit{3}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \\
-    & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{3}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \verb|=?=| \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{2}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{28}{\isacharparenleft}}{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \\
     & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{3}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \verb|==| \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{2}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{28}{\isacharparenleft}}{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \\
     & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{3}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C65717569763E}{\isasymequiv}}{\isaliteral{22}{\isachardoublequote}}} \isa{{\isaliteral{22}{\isachardoublequote}}any\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{2}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{28}{\isacharparenleft}}{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \\
     & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}prop\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{3}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \verb|&&&| \isa{{\isaliteral{22}{\isachardoublequote}}prop\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{28}{\isacharparenleft}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isadigit{2}}\isaliteral{5C3C5E7375703E}{}\isactrlsup {\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{28}{\isacharparenleft}}{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}} \\

--- a/src/Pure/Syntax/simple_syntax.ML	Thu Apr 07 20:56:48 2011 +0200
+++ b/src/Pure/Syntax/simple_syntax.ML	Thu Apr 07 21:23:57 2011 +0200
@@ -17,7 +17,7 @@
 (* scanning tokens *)
 
 val lexicon = Scan.make_lexicon
-  (map Symbol.explode ["!!", "%", "(", ")", ".", "::", "==", "==>", "=?=", "=>", "&&&", "CONST"]);
+  (map Symbol.explode ["!!", "%", "(", ")", ".", "::", "==", "==>", "=>", "&&&", "CONST"]);
 
 fun read scan s =
   (case
@@ -79,7 +79,6 @@
   term1 = term2 ==> ... ==> term2
         | term2
   term2 = term3 == term2
-        | term3 =?= term2
         | term3 &&& term2
         | term3
   term3 = ident :: typ
@@ -109,7 +108,7 @@
  (enum2 "==>" (term2 env propT) >> foldr1 Logic.mk_implies ||
   term2 env T) x
 and term2 env T x =
- (equal env "==" || equal env "=?=" ||
+ (equal env "==" ||
   term3 env propT -- ($$ "&&&" |-- term2 env propT) >> Logic.mk_conjunction ||
   term3 env T) x
 and equal env eq x =

--- a/src/Pure/unify.ML	Thu Apr 07 20:56:48 2011 +0200
+++ b/src/Pure/unify.ML	Thu Apr 07 21:23:57 2011 +0200
@@ -596,7 +596,7 @@
       let
         fun termT t =
           Syntax.pretty_term_global thy (Envir.norm_term env (Logic.rlist_abs (rbinder, t)));
-        val bsymbs = [termT u, Pretty.str" =?=", Pretty.brk 1, termT t];
+        val bsymbs = [termT u, Pretty.str " =?=", Pretty.brk 1, termT t];
       in tracing (Pretty.string_of (Pretty.blk (0, bsymbs))) end;
   in tracing msg; List.app pdp dpairs end;