diff --git a/src/HOL/Tools/Nitpick/nitpick_util.ML b/src/HOL/Tools/Nitpick/nitpick_util.ML
--- a/src/HOL/Tools/Nitpick/nitpick_util.ML
+++ b/src/HOL/Tools/Nitpick/nitpick_util.ML
@@ -1,310 +1,313 @@
 (*  Title:      HOL/Tools/Nitpick/nitpick_util.ML
     Author:     Jasmin Blanchette, TU Muenchen
     Copyright   2008, 2009, 2010
 
 General-purpose functions used by the Nitpick modules.
 *)
 
 signature NITPICK_UTIL =
 sig
   datatype polarity = Pos | Neg | Neut
 
   exception ARG of string * string
   exception BAD of string * string
   exception TOO_SMALL of string * string
   exception TOO_LARGE of string * string
   exception NOT_SUPPORTED of string
   exception SAME of unit
 
   val nitpick_prefix : string
   val curry3 : ('a * 'b * 'c -> 'd) -> 'a -> 'b -> 'c -> 'd
   val pairf : ('a -> 'b) -> ('a -> 'c) -> 'a -> 'b * 'c
   val pair_from_fun : (bool -> 'a) -> 'a * 'a
   val fun_from_pair : 'a * 'a -> bool -> 'a
   val int_from_bool : bool -> int
   val nat_minus : int -> int -> int
   val reasonable_power : int -> int -> int
   val exact_log : int -> int -> int
   val exact_root : int -> int -> int
   val offset_list : int list -> int list
   val index_seq : int -> int -> int list
   val filter_indices : int list -> 'a list -> 'a list
   val filter_out_indices : int list -> 'a list -> 'a list
   val fold1 : ('a -> 'a -> 'a) -> 'a list -> 'a
   val replicate_list : int -> 'a list -> 'a list
   val n_fold_cartesian_product : 'a list list -> 'a list list
   val all_distinct_unordered_pairs_of : ''a list -> (''a * ''a) list
   val nth_combination : (int * int) list -> int -> int list
   val all_combinations : (int * int) list -> int list list
   val all_permutations : 'a list -> 'a list list
   val chunk_list : int -> 'a list -> 'a list list
   val chunk_list_unevenly : int list -> 'a list -> 'a list list
   val double_lookup :
     ('a * 'a -> bool) -> ('a option * 'b) list -> 'a -> 'b option
   val triple_lookup :
     (''a * ''a -> bool) -> (''a option * 'b) list -> ''a -> 'b option
   val is_substring_of : string -> string -> bool
   val plural_s : int -> string
   val plural_s_for_list : 'a list -> string
   val serial_commas : string -> string list -> string list
   val pretty_serial_commas : string -> Pretty.T list -> Pretty.T list
   val parse_bool_option : bool -> string -> string -> bool option
   val parse_time : string -> string -> Time.time
   val string_of_time : Time.time -> string
   val nat_subscript : int -> string
   val flip_polarity : polarity -> polarity
   val prop_T : typ
   val bool_T : typ
   val nat_T : typ
   val int_T : typ
   val simple_string_of_typ : typ -> string
   val num_binder_types : typ -> int
   val varify_type : Proof.context -> typ -> typ
   val instantiate_type : theory -> typ -> typ -> typ -> typ
   val varify_and_instantiate_type : Proof.context -> typ -> typ -> typ -> typ
   val varify_and_instantiate_type_global : theory -> typ -> typ -> typ -> typ
   val is_of_class_const : theory -> string * typ -> bool
   val get_class_def : theory -> string -> (string * term) option
   val specialize_type : theory -> string * typ -> term -> term
   val eta_expand : typ list -> term -> int -> term
   val DETERM_TIMEOUT : Time.time -> tactic -> tactic
   val indent_size : int
   val pretty_maybe_quote : Proof.context -> Pretty.T -> Pretty.T
   val hash_term : term -> int
   val spying : bool -> (unit -> Proof.state * int * string) -> unit
 end;
 
 structure Nitpick_Util : NITPICK_UTIL =
 struct
 
 datatype polarity = Pos | Neg | Neut
 
 exception ARG of string * string
 exception BAD of string * string
 exception TOO_SMALL of string * string
 exception TOO_LARGE of string * string
 exception NOT_SUPPORTED of string
 exception SAME of unit
 
 val nitpick_prefix = "Nitpick" ^ Long_Name.separator
 
 val timestamp = ATP_Util.timestamp
 
 fun curry3 f = fn x => fn y => fn z => f (x, y, z)
 
 fun pairf f g x = (f x, g x)
 
 fun pair_from_fun f = (f false, f true)
 fun fun_from_pair (f, t) b = if b then t else f
 
 fun int_from_bool b = if b then 1 else 0
 fun nat_minus i j = if i > j then i - j else 0
 
 val max_exponent = 16384
 
 fun reasonable_power _ 0 = 1
   | reasonable_power a 1 = a
   | reasonable_power 0 _ = 0
   | reasonable_power 1 _ = 1
   | reasonable_power a b =
     if b < 0 then
       raise ARG ("Nitpick_Util.reasonable_power",
                  "negative exponent (" ^ signed_string_of_int b ^ ")")
     else if b > max_exponent then
       raise TOO_LARGE ("Nitpick_Util.reasonable_power",
                        "too large exponent (" ^ signed_string_of_int a ^ " ^ " ^
                        signed_string_of_int b ^ ")")
     else
       let val c = reasonable_power a (b div 2) in
         c * c * reasonable_power a (b mod 2)
       end
 
 fun exact_log m n =
   let
     val r = Math.ln (Real.fromInt n) / Math.ln (Real.fromInt m) |> Real.round
   in
     if reasonable_power m r = n then
       r
     else
       raise ARG ("Nitpick_Util.exact_log",
                  commas (map signed_string_of_int [m, n]))
   end
 
 fun exact_root m n =
   let val r = Math.pow (Real.fromInt n, 1.0 / (Real.fromInt m)) |> Real.round in
     if reasonable_power r m = n then
       r
     else
       raise ARG ("Nitpick_Util.exact_root",
                  commas (map signed_string_of_int [m, n]))
   end
 
 fun fold1 f = foldl1 (uncurry f)
 
 fun replicate_list 0 _ = []
   | replicate_list n xs = xs @ replicate_list (n - 1) xs
 
 fun offset_list ns = rev (tl (fold (fn x => fn xs => (x + hd xs) :: xs) ns [0]))
 
 fun index_seq j0 n = if j0 < 0 then j0 downto j0 - n + 1 else j0 upto j0 + n - 1
 
 fun filter_indices js xs =
   let
     fun aux _ [] _ = []
       | aux i (j :: js) (x :: xs) =
         if i = j then x :: aux (i + 1) js xs else aux (i + 1) (j :: js) xs
       | aux _ _ _ = raise ARG ("Nitpick_Util.filter_indices",
                                "indices unordered or out of range")
   in aux 0 js xs end
 
 fun filter_out_indices js xs =
   let
     fun aux _ [] xs = xs
       | aux i (j :: js) (x :: xs) =
         if i = j then aux (i + 1) js xs else x :: aux (i + 1) (j :: js) xs
       | aux _ _ _ = raise ARG ("Nitpick_Util.filter_out_indices",
                                "indices unordered or out of range")
   in aux 0 js xs end
 
 fun cartesian_product [] _ = []
   | cartesian_product (x :: xs) yss = map (cons x) yss @ cartesian_product xs yss
 
 fun n_fold_cartesian_product xss = fold_rev cartesian_product xss [[]]
 
 fun all_distinct_unordered_pairs_of [] = []
   | all_distinct_unordered_pairs_of (x :: xs) =
     map (pair x) xs @ all_distinct_unordered_pairs_of xs
 
 val nth_combination =
   let
     fun aux [] n = ([], n)
       | aux ((k, j0) :: xs) n =
         let val (js, n) = aux xs n in ((n mod k) + j0 :: js, n div k) end
   in fst oo aux end
 
 val all_combinations = n_fold_cartesian_product o map (uncurry index_seq o swap)
 
 fun all_permutations [] = [[]]
   | all_permutations xs =
     maps (fn j => map (cons (nth xs j)) (all_permutations (nth_drop j xs)))
          (index_seq 0 (length xs))
 
 (* FIXME: use "Library.chop_groups" *)
 val chunk_list = ATP_Util.chunk_list
 
 (* FIXME: use "Library.unflat" *)
 fun chunk_list_unevenly _ [] = []
   | chunk_list_unevenly [] xs = map single xs
   | chunk_list_unevenly (k :: ks) xs =
     let val (xs1, xs2) = chop k xs in xs1 :: chunk_list_unevenly ks xs2 end
 
 fun double_lookup eq ps key =
   case AList.lookup (fn (SOME x, SOME y) => eq (x, y) | _ => false) ps
                     (SOME key) of
     SOME z => SOME z
   | NONE => ps |> find_first (is_none o fst) |> Option.map snd
 
 fun triple_lookup _ [(NONE, z)] _ = SOME z
   | triple_lookup eq ps key =
     case AList.lookup (op =) ps (SOME key) of
       SOME z => SOME z
     | NONE => double_lookup eq ps key
 
 fun is_substring_of needle stack =
   not (Substring.isEmpty (snd (Substring.position needle
                                                   (Substring.full stack))))
 
 val plural_s = Sledgehammer_Util.plural_s
 fun plural_s_for_list xs = plural_s (length xs)
 
 val serial_commas = Try.serial_commas
 
 fun pretty_serial_commas _ [] = []
   | pretty_serial_commas _ [p] = [p]
   | pretty_serial_commas conj [p1, p2] =
     [p1, Pretty.brk 1, Pretty.str conj, Pretty.brk 1, p2]
   | pretty_serial_commas conj [p1, p2, p3] =
     [p1, Pretty.str ",", Pretty.brk 1, p2, Pretty.str ",", Pretty.brk 1,
      Pretty.str conj, Pretty.brk 1, p3]
   | pretty_serial_commas conj (p :: ps) =
     p :: Pretty.str "," :: Pretty.brk 1 :: pretty_serial_commas conj ps
 
 val parse_bool_option = Sledgehammer_Util.parse_bool_option
 val parse_time = Sledgehammer_Util.parse_time
 val string_of_time = ATP_Util.string_of_time
 
 val subscript = implode o map (prefix "\<^sub>") o Symbol.explode
 
 fun nat_subscript n =
   n |> signed_string_of_int |> not (print_mode_active Print_Mode.ASCII) ? subscript
 
 fun flip_polarity Pos = Neg
   | flip_polarity Neg = Pos
   | flip_polarity Neut = Neut
 
 val prop_T = \<^typ>\<open>prop\<close>
 val bool_T = \<^typ>\<open>bool\<close>
 val nat_T = \<^typ>\<open>nat\<close>
 val int_T = \<^typ>\<open>int\<close>
 
 fun simple_string_of_typ (Type (s, _)) = s
   | simple_string_of_typ (TFree (s, _)) = s
   | simple_string_of_typ (TVar ((s, _), _)) = s
 
 val num_binder_types = BNF_Util.num_binder_types
 
 val varify_type = ATP_Util.varify_type
 val instantiate_type = ATP_Util.instantiate_type
 val varify_and_instantiate_type = ATP_Util.varify_and_instantiate_type
 
 fun varify_and_instantiate_type_global thy T1 T1' T2 =
   instantiate_type thy (Logic.varifyT_global T1) T1' (Logic.varifyT_global T2)
 
 fun is_of_class_const thy (s, _) =
   member (op =) (map Logic.const_of_class (Sign.all_classes thy)) s
 
 fun get_class_def thy class =
   let val axname = class ^ "_class_def" in
     Option.map (pair axname)
       (AList.lookup (op =) (Theory.all_axioms_of thy) axname)
   end;
 
 val specialize_type = ATP_Util.specialize_type
 val eta_expand = ATP_Util.eta_expand
 
 fun DETERM_TIMEOUT delay tac st =
   Seq.of_list (the_list (Timeout.apply delay (fn () => SINGLE tac st) ()))
 
 val indent_size = 2
 
 fun pretty_maybe_quote ctxt pretty =
-  let val s = Pretty.unformatted_string_of pretty
-  in if ATP_Util.maybe_quote ctxt s = s then pretty else Pretty.quote pretty end
+  let val s = Pretty.unformatted_string_of pretty in
+    if ATP_Util.maybe_quote ctxt s = s then pretty
+    else if Config.get ctxt ATP_Util.proof_cartouches then Pretty.cartouche pretty
+    else Pretty.quote pretty
+  end
 
 val hashw = ATP_Util.hashw
 val hashw_string = ATP_Util.hashw_string
 
 fun hashw_term (t1 $ t2) = hashw (hashw_term t1, hashw_term t2)
   | hashw_term (Const (s, _)) = hashw_string (s, 0w0)
   | hashw_term (Free (s, _)) = hashw_string (s, 0w0)
   | hashw_term _ = 0w0
 
 val hash_term = Word.toInt o hashw_term
 
 val hackish_string_of_term = Sledgehammer_Util.hackish_string_of_term
 
 val spying_version = "b"
 
 fun spying false _ = ()
   | spying true f =
     let
       val (state, i, message) = f ()
       val ctxt = Proof.context_of state
       val goal = Logic.get_goal (Thm.prop_of (#goal (Proof.goal state))) i
       val hash = String.substring (SHA1.rep (SHA1.digest (hackish_string_of_term ctxt goal)), 0, 12)
     in
       File.append (Path.explode "$ISABELLE_HOME_USER/spy_nitpick")
         (spying_version ^ " " ^ timestamp () ^ ": " ^ hash ^ ": " ^ message ^ "\n")
     end
 
 end;