diff --git a/src/Pure/Syntax/syntax_trans.ML b/src/Pure/Syntax/syntax_trans.ML
--- a/src/Pure/Syntax/syntax_trans.ML
+++ b/src/Pure/Syntax/syntax_trans.ML
@@ -1,505 +1,502 @@
 (*  Title:      Pure/Syntax/syntax_trans.ML
     Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen
 
 Syntax translation functions.
 *)
 
 signature BASIC_SYNTAX_TRANS =
 sig
   val eta_contract: bool Config.T
 end
 
 signature SYNTAX_TRANS =
 sig
   include BASIC_SYNTAX_TRANS
   val bracketsN: string
   val no_bracketsN: string
   val no_brackets: unit -> bool
   val type_bracketsN: string
   val no_type_bracketsN: string
   val no_type_brackets: unit -> bool
   val abs_tr: term list -> term
   val mk_binder_tr: string * string -> string * (Proof.context -> term list -> term)
   val antiquote_tr: string -> term -> term
   val quote_tr: string -> term -> term
   val quote_antiquote_tr: string -> string -> string ->
     string * (Proof.context -> term list -> term)
   val non_typed_tr': (Proof.context -> term list -> term) ->
     Proof.context -> typ -> term list -> term
   val tappl_ast_tr': Ast.ast * Ast.ast list -> Ast.ast
   val appl_ast_tr': Ast.ast * Ast.ast list -> Ast.ast
   val applC_ast_tr': Ast.ast * Ast.ast list -> Ast.ast
   val mark_bound_abs: string * typ -> term
   val mark_bound_body: string * typ -> term
   val bound_vars: (string * typ) list -> term -> term
   val abs_tr': Proof.context -> term -> term
   val atomic_abs_tr': string * typ * term -> term * term
   val const_abs_tr': term -> term
   val mk_binder_tr': string * string -> string * (Proof.context -> term list -> term)
   val preserve_binder_abs_tr': string -> string -> string * (Proof.context -> term list -> term)
   val preserve_binder_abs2_tr': string -> string -> string * (Proof.context -> term list -> term)
   val variant_abs: string * typ * term -> string * term
   val variant_abs': string * typ * term -> string * term
   val dependent_tr': string * string -> term list -> term
   val antiquote_tr': string -> term -> term
   val quote_tr': string -> term -> term
   val quote_antiquote_tr': string -> string -> string ->
     string * (Proof.context -> term list -> term)
   val update_name_tr': term -> term
   val get_idents: Proof.context -> {structs: string list, fixes: string list}
   val put_idents: {structs: string list, fixes: string list} -> Proof.context -> Proof.context
   val pure_parse_ast_translation: (string * (Proof.context -> Ast.ast list -> Ast.ast)) list
   val pure_parse_translation: (string * (Proof.context -> term list -> term)) list
   val pure_print_ast_translation: (string * (Proof.context -> Ast.ast list -> Ast.ast)) list
 end;
 
 structure Syntax_Trans: SYNTAX_TRANS =
 struct
 
 structure Syntax = Lexicon.Syntax;
 
 
 (* print mode *)
 
 val bracketsN = "brackets";
 val no_bracketsN = "no_brackets";
 
 fun no_brackets () =
   find_first (fn mode => mode = bracketsN orelse mode = no_bracketsN)
     (print_mode_value ()) = SOME no_bracketsN;
 
 val type_bracketsN = "type_brackets";
 val no_type_bracketsN = "no_type_brackets";
 
 fun no_type_brackets () =
   find_first (fn mode => mode = type_bracketsN orelse mode = no_type_bracketsN)
     (print_mode_value ()) <> SOME type_bracketsN;
 
 
 
 (** parse (ast) translations **)
 
 (* strip_positions *)
 
 fun strip_positions_ast_tr [ast] = Ast.strip_positions ast
   | strip_positions_ast_tr asts = raise Ast.AST ("strip_positions_ast_tr", asts);
 
 
 (* constify *)
 
 fun constify_ast_tr [Ast.Appl [c as Ast.Constant "_constrain", ast1, ast2]] =
       Ast.Appl [c, constify_ast_tr [ast1], ast2]
   | constify_ast_tr [Ast.Variable c] = Ast.Constant c
   | constify_ast_tr asts = raise Ast.AST ("constify_ast_tr", asts);
 
 
 (* type syntax *)
 
 fun tapp_ast_tr [ty, c] = Ast.Appl [c, ty]
   | tapp_ast_tr asts = raise Ast.AST ("tapp_ast_tr", asts);
 
 fun tappl_ast_tr [ty, tys, c] = Ast.mk_appl c (ty :: Ast.unfold_ast "_types" tys)
   | tappl_ast_tr asts = raise Ast.AST ("tappl_ast_tr", asts);
 
 fun bracket_ast_tr [dom, cod] = Ast.fold_ast_p "\<^type>fun" (Ast.unfold_ast "_types" dom, cod)
   | bracket_ast_tr asts = raise Ast.AST ("bracket_ast_tr", asts);
 
 
 (* application *)
 
 fun appl_ast_tr [f, args] = Ast.Appl (f :: Ast.unfold_ast "_args" args)
   | appl_ast_tr asts = raise Ast.AST ("appl_ast_tr", asts);
 
 fun applC_ast_tr [f, args] = Ast.Appl (f :: Ast.unfold_ast "_cargs" args)
   | applC_ast_tr asts = raise Ast.AST ("applC_ast_tr", asts);
 
 
 (* abstraction *)
 
 fun idtyp_ast_tr [x, ty] = Ast.Appl [Ast.Constant "_constrain", x, ty]
   | idtyp_ast_tr asts = raise Ast.AST ("idtyp_ast_tr", asts);
 
 fun lambda_ast_tr [pats, body] = Ast.fold_ast_p "_abs" (Ast.unfold_ast "_pttrns" pats, body)
   | lambda_ast_tr asts = raise Ast.AST ("lambda_ast_tr", asts);
 
 fun absfree_proper (x, T) t =
   if Name.is_internal x
   then error ("Illegal internal variable in abstraction: " ^ quote x)
   else absfree (x, T) t;
 
 fun abs_tr [Free x, t] = absfree_proper x t
   | abs_tr [Const ("_idtdummy", T), t] = absdummy T t
-  | abs_tr [Const ("_constrain", _) $ x $ tT, t] =
-      Syntax.const "_constrainAbs" $ abs_tr [x, t] $ tT
+  | abs_tr [Const ("_constrain", _) $ x $ tT, t] = Syntax.const "_constrainAbs" $ abs_tr [x, t] $ tT
   | abs_tr ts = raise TERM ("abs_tr", ts);
 
 
 (* binder *)
 
 fun mk_binder_tr (syn, name) =
   let
     fun err ts = raise TERM ("binder_tr: " ^ syn, ts)
     fun binder_tr [Const ("_idts", _) $ idt $ idts, t] = binder_tr [idt, binder_tr [idts, t]]
-      | binder_tr [x, t] =
-          let val abs = abs_tr [x, t] handle TERM _ => err [x, t]
-          in Syntax.const name $ abs end
+      | binder_tr [x, t] = Syntax.const name $ (abs_tr [x, t] handle TERM _ => err [x, t])
       | binder_tr ts = err ts;
   in (syn, fn _ => binder_tr) end;
 
 
 (* type propositions *)
 
 fun mk_type ty =
   Syntax.const "_constrain" $
     Syntax.const "\<^const>Pure.type" $ (Syntax.const "\<^type>itself" $ ty);
 
 fun ofclass_tr [ty, cls] = cls $ mk_type ty
   | ofclass_tr ts = raise TERM ("ofclass_tr", ts);
 
 fun sort_constraint_tr [ty] = Syntax.const "\<^const>Pure.sort_constraint" $ mk_type ty
   | sort_constraint_tr ts = raise TERM ("sort_constraint_tr", ts);
 
 
 (* meta propositions *)
 
 fun aprop_tr [t] = Syntax.const "_constrain" $ t $ Syntax.const "\<^type>prop"
   | aprop_tr ts = raise TERM ("aprop_tr", ts);
 
 
 (* meta implication *)
 
 fun bigimpl_ast_tr (asts as [asms, concl]) =
       let val prems =
         (case Ast.unfold_ast_p "_asms" asms of
           (asms', Ast.Appl [Ast.Constant "_asm", asm']) => asms' @ [asm']
         | _ => raise Ast.AST ("bigimpl_ast_tr", asts))
       in Ast.fold_ast_p "\<^const>Pure.imp" (prems, concl) end
   | bigimpl_ast_tr asts = raise Ast.AST ("bigimpl_ast_tr", asts);
 
 
 (* type/term reflection *)
 
 fun type_tr [ty] = mk_type ty
   | type_tr ts = raise TERM ("type_tr", ts);
 
 
 (* quote / antiquote *)
 
 fun antiquote_tr name =
   let
     fun tr i ((t as Const (c, _)) $ u) =
           if c = name then tr i u $ Bound i
           else tr i t $ tr i u
       | tr i (t $ u) = tr i t $ tr i u
       | tr i (Abs (x, T, t)) = Abs (x, T, tr (i + 1) t)
       | tr _ a = a;
   in tr 0 end;
 
 fun quote_tr name t = Abs ("s", dummyT, antiquote_tr name (Term.incr_boundvars 1 t));
 
 fun quote_antiquote_tr quoteN antiquoteN name =
   let
     fun tr [t] = Syntax.const name $ quote_tr antiquoteN t
       | tr ts = raise TERM ("quote_tr", ts);
   in (quoteN, fn _ => tr) end;
 
 
 (* corresponding updates *)
 
 fun update_name_tr (Free (x, T) :: ts) = list_comb (Free (suffix "_update" x, T), ts)
   | update_name_tr (Const (x, T) :: ts) = list_comb (Const (suffix "_update" x, T), ts)
   | update_name_tr (((c as Const ("_constrain", _)) $ t $ ty) :: ts) =
       if Term_Position.is_position ty then list_comb (c $ update_name_tr [t] $ ty, ts)
       else
         list_comb (c $ update_name_tr [t] $
           (Lexicon.fun_type $
             (Lexicon.fun_type $ Lexicon.dummy_type $ ty) $ Lexicon.dummy_type), ts)
   | update_name_tr ts = raise TERM ("update_name_tr", ts);
 
 
 (* indexed syntax *)
 
 structure Idents = Proof_Data
 (
   type T = {structs: string list, fixes: string list};
   fun init _ : T = {structs = [], fixes = []};
 );
 
 val get_idents = Idents.get;
 val put_idents = Idents.put;
 
 fun indexdefault_ast_tr [] =
       Ast.Appl [Ast.Constant "_index",
         Ast.Appl [Ast.Constant "_struct", Ast.Constant "_indexdefault"]]
   | indexdefault_ast_tr asts = raise Ast.AST ("indexdefault_ast_tr", asts);
 
 fun indexvar_ast_tr [] = Ast.Appl [Ast.Constant "_index", Ast.Variable "some_index"]
   | indexvar_ast_tr asts = raise Ast.AST ("indexvar_ast_tr", asts);
 
 fun struct_ast_tr [Ast.Appl [Ast.Constant "_index", ast]] = ast
   | struct_ast_tr asts = Ast.mk_appl (Ast.Constant "_struct") asts;
 
 fun index_tr [t] = t
   | index_tr ts = raise TERM ("index_tr", ts);
 
 fun struct_tr ctxt [Const ("_indexdefault", _)] =
       (case #structs (get_idents ctxt) of
         x :: _ => Syntax.const (Lexicon.mark_fixed x)
       | _ => error "Illegal reference to implicit structure")
   | struct_tr _ ts = raise TERM ("struct_tr", ts);
 
 
 
 (** print (ast) translations **)
 
 (* types *)
 
 fun non_typed_tr' f ctxt _ ts = f ctxt ts;
 
 
 (* type syntax *)
 
 fun tappl_ast_tr' (f, []) = raise Ast.AST ("tappl_ast_tr'", [f])
   | tappl_ast_tr' (f, [ty]) = Ast.Appl [Ast.Constant "_tapp", ty, f]
   | tappl_ast_tr' (f, ty :: tys) =
       Ast.Appl [Ast.Constant "_tappl", ty, Ast.fold_ast "_types" tys, f];
 
 fun fun_ast_tr' asts =
   if no_brackets () orelse no_type_brackets () then raise Match
   else
     (case Ast.unfold_ast_p "\<^type>fun" (Ast.Appl (Ast.Constant "\<^type>fun" :: asts)) of
       (dom as _ :: _ :: _, cod)
         => Ast.Appl [Ast.Constant "_bracket", Ast.fold_ast "_types" dom, cod]
     | _ => raise Match);
 
 
 (* application *)
 
 fun appl_ast_tr' (f, []) = raise Ast.AST ("appl_ast_tr'", [f])
   | appl_ast_tr' (f, args) = Ast.Appl [Ast.Constant "_appl", f, Ast.fold_ast "_args" args];
 
 fun applC_ast_tr' (f, []) = raise Ast.AST ("applC_ast_tr'", [f])
   | applC_ast_tr' (f, args) = Ast.Appl [Ast.Constant "_applC", f, Ast.fold_ast "_cargs" args];
 
 
 (* partial eta-contraction before printing *)
 
 fun eta_abs (Abs (a, T, t)) =
       (case eta_abs t of
         t' as Const ("_aprop", _) $ _ => Abs (a, T, t')
       | t' as f $ u =>
           (case eta_abs u of
             Bound 0 =>
               if Term.is_dependent f then Abs (a, T, t')
               else incr_boundvars ~1 f
           | _ => Abs (a, T, t'))
       | t' => Abs (a, T, t'))
   | eta_abs t = t;
 
 val eta_contract = Config.declare_option_bool ("eta_contract", \<^here>);
 fun eta_contr ctxt = Config.get ctxt eta_contract ? eta_abs;
 
 
 (* abstraction *)
 
 fun mark_bound_abs (x, T) = Const ("_bound", T --> T) $ Free (x, T);
 fun mark_bound_body (x, T) = Const ("_bound", dummyT) $ Free (x, T);
 
 fun bound_vars vars body =
   subst_bounds (map mark_bound_abs (Term.rename_wrt_term body vars), body);
 
 fun strip_abss vars_of body_of tm =
   let
     val vars = vars_of tm;
     val body = body_of tm;
     val rev_new_vars = Term.rename_wrt_term body vars;
     fun subst (x, T) b =
       if Name.is_internal x andalso not (Term.is_dependent b)
       then (Const ("_idtdummy", T), incr_boundvars ~1 b)
       else (mark_bound_abs (x, T), Term.subst_bound (mark_bound_body (x, T), b));
     val (rev_vars', body') = fold_map subst rev_new_vars body;
   in (rev rev_vars', body') end;
 
 
 fun abs_tr' ctxt tm =
   uncurry (fold_rev (fn x => fn t => Syntax.const "_abs" $ x $ t))
     (strip_abss strip_abs_vars strip_abs_body (eta_contr ctxt tm));
 
 fun atomic_abs_tr' (x, T, t) =
   let val [xT] = Term.rename_wrt_term t [(x, T)]
   in (mark_bound_abs xT, subst_bound (mark_bound_body xT, t)) end;
 
 fun abs_ast_tr' asts =
   (case Ast.unfold_ast_p "_abs" (Ast.Appl (Ast.Constant "_abs" :: asts)) of
     ([], _) => raise Ast.AST ("abs_ast_tr'", asts)
   | (xs, body) => Ast.Appl [Ast.Constant "_lambda", Ast.fold_ast "_pttrns" xs, body]);
 
 fun const_abs_tr' t =
   (case eta_abs t of
     Abs (_, _, t') =>
       if Term.is_dependent t' then raise Match
       else incr_boundvars ~1 t'
   | _ => raise Match);
 
 
 (* binders *)
 
 fun mk_binder_tr' (name, syn) =
   let
     fun mk_idts [] = raise Match    (*abort translation*)
       | mk_idts [idt] = idt
       | mk_idts (idt :: idts) = Syntax.const "_idts" $ idt $ mk_idts idts;
 
     fun tr' t =
       let
         val (xs, bd) = strip_abss (strip_qnt_vars name) (strip_qnt_body name) t;
       in Syntax.const syn $ mk_idts xs $ bd end;
 
     fun binder_tr' (t :: ts) = Term.list_comb (tr' (Syntax.const name $ t), ts)
       | binder_tr' [] = raise Match;
   in (name, fn _ => binder_tr') end;
 
 fun preserve_binder_abs_tr' name syn = (name, fn _ => fn Abs abs :: ts =>
   let val (x, t) = atomic_abs_tr' abs
   in list_comb (Syntax.const syn $ x $ t, ts) end);
 
 fun preserve_binder_abs2_tr' name syn = (name, fn _ => fn A :: Abs abs :: ts =>
   let val (x, t) = atomic_abs_tr' abs
   in list_comb (Syntax.const syn $ x $ A $ t, ts) end);
 
 
 (* idtyp constraints *)
 
 fun idtyp_ast_tr' a [Ast.Appl [Ast.Constant "_constrain", x, ty], xs] =
       Ast.Appl [Ast.Constant a, Ast.Appl [Ast.Constant "_idtyp", x, ty], xs]
   | idtyp_ast_tr' _ _ = raise Match;
 
 
 (* meta implication *)
 
 fun impl_ast_tr' asts =
   if no_brackets () then raise Match
   else
     (case Ast.unfold_ast_p "\<^const>Pure.imp"
         (Ast.Appl (Ast.Constant "\<^const>Pure.imp" :: asts)) of
       (prems as _ :: _ :: _, concl) =>
         let
           val (asms, asm) = split_last prems;
           val asms' = Ast.fold_ast_p "_asms" (asms, Ast.Appl [Ast.Constant "_asm", asm]);
         in Ast.Appl [Ast.Constant "_bigimpl", asms', concl] end
     | _ => raise Match);
 
 
 (* dependent / nondependent quantifiers *)
 
 fun var_abs mark (x, T, b) =
   let val (x', _) = Name.variant x (Term.declare_term_names b Name.context)
   in (x', subst_bound (mark (x', T), b)) end;
 
 val variant_abs = var_abs Free;
 val variant_abs' = var_abs mark_bound_abs;
 
 fun dependent_tr' (q, r) (A :: Abs (x, T, B) :: ts) =
       if Term.is_dependent B then
         let val (x', B') = variant_abs' (x, dummyT, B);
         in Term.list_comb (Syntax.const q $ mark_bound_abs (x', T) $ A $ B', ts) end
       else Term.list_comb (Syntax.const r $ A $ incr_boundvars ~1 B, ts)
   | dependent_tr' _ _ = raise Match;
 
 
 (* quote / antiquote *)
 
 fun antiquote_tr' name =
   let
     fun tr' i (t $ u) =
           if u aconv Bound i then Syntax.const name $ tr' i t
           else tr' i t $ tr' i u
       | tr' i (Abs (x, T, t)) = Abs (x, T, tr' (i + 1) t)
       | tr' i a = if a aconv Bound i then raise Match else a;
   in tr' 0 end;
 
 fun quote_tr' name (Abs (_, _, t)) = Term.incr_boundvars ~1 (antiquote_tr' name t)
   | quote_tr' _ _ = raise Match;
 
 fun quote_antiquote_tr' quoteN antiquoteN name =
   let
     fun tr' (t :: ts) = Term.list_comb (Syntax.const quoteN $ quote_tr' antiquoteN t, ts)
       | tr' _ = raise Match;
   in (name, fn _ => tr') end;
 
 
 (* corresponding updates *)
 
 local
 
 fun upd_type (Type ("fun", [Type ("fun", [_, T]), _])) = T
   | upd_type _ = dummyT;
 
 fun upd_tr' (x_upd, T) =
   (case try (unsuffix "_update") x_upd of
     SOME x => (x, upd_type T)
   | NONE => raise Match);
 
 in
 
 fun update_name_tr' (Free x) = Free (upd_tr' x)
   | update_name_tr' ((c as Const ("_free", _)) $ Free x) = c $ Free (upd_tr' x)
   | update_name_tr' (Const x) = Const (upd_tr' x)
   | update_name_tr' _ = raise Match;
 
 end;
 
 
 (* indexed syntax *)
 
 fun index_ast_tr' [Ast.Appl [Ast.Constant "_struct", ast]] = ast
   | index_ast_tr' _ = raise Match;
 
 fun struct_ast_tr' ctxt [Ast.Constant "_indexdefault"] =
       (case #structs (get_idents ctxt) of
         x :: _ => Ast.Appl [Ast.Constant "_free", Ast.Variable x]
       | _ => raise Match)
   | struct_ast_tr' _ _ = raise Match;
 
 
 
 (** Pure translations **)
 
 val pure_parse_ast_translation =
  [("_strip_positions", fn _ => strip_positions_ast_tr),
   ("_constify", fn _ => constify_ast_tr),
   ("_tapp", fn _ => tapp_ast_tr),
   ("_tappl", fn _ => tappl_ast_tr),
   ("_bracket", fn _ => bracket_ast_tr),
   ("_appl", fn _ => appl_ast_tr),
   ("_applC", fn _ => applC_ast_tr),
   ("_lambda", fn _ => lambda_ast_tr),
   ("_idtyp", fn _ => idtyp_ast_tr),
   ("_bigimpl", fn _ => bigimpl_ast_tr),
   ("_indexdefault", fn _ => indexdefault_ast_tr),
   ("_indexvar", fn _ => indexvar_ast_tr),
   ("_struct", fn _ => struct_ast_tr)];
 
 val pure_parse_translation =
  [("_abs", fn _ => abs_tr),
   ("_aprop", fn _ => aprop_tr),
   ("_ofclass", fn _ => ofclass_tr),
   ("_sort_constraint", fn _ => sort_constraint_tr),
   ("_TYPE", fn _ => type_tr),
   ("_update_name", fn _ => update_name_tr),
   ("_index", fn _ => index_tr),
   ("_struct", struct_tr)];
 
 val pure_print_ast_translation =
  [("\<^type>fun", fn _ => fun_ast_tr'),
   ("_abs", fn _ => abs_ast_tr'),
   ("_idts", fn _ => idtyp_ast_tr' "_idts"),
   ("_pttrns", fn _ => idtyp_ast_tr' "_pttrns"),
   ("\<^const>Pure.imp", fn _ => impl_ast_tr'),
   ("_index", fn _ => index_ast_tr'),
   ("_struct", struct_ast_tr')];
 
 end;
 
 structure Basic_Syntax_Trans: BASIC_SYNTAX_TRANS = Syntax_Trans;
 open Basic_Syntax_Trans;