diff --git a/src/Pure/Thy/document_output.ML b/src/Pure/Thy/document_output.ML
--- a/src/Pure/Thy/document_output.ML
+++ b/src/Pure/Thy/document_output.ML
@@ -1,573 +1,573 @@
 (*  Title:      Pure/Thy/document_output.ML
     Author:     Makarius
 
 Theory document output.
 *)
 
 signature DOCUMENT_OUTPUT =
 sig
   val document_reports: Input.source -> Position.report list
   val output_document: Proof.context -> {markdown: bool} -> Input.source -> Latex.text
   val check_comments: Proof.context -> Symbol_Pos.T list -> unit
   val output_token: Proof.context -> Token.T -> Latex.text
   val output_source: Proof.context -> string -> Latex.text
   type segment =
     {span: Command_Span.span, command: Toplevel.transition,
      prev_state: Toplevel.state, state: Toplevel.state}
   val present_thy: Options.T -> theory -> segment list -> Latex.text
   val pretty_term: Proof.context -> term -> Pretty.T
   val pretty_thm: Proof.context -> thm -> Pretty.T
   val isabelle: Proof.context -> Latex.text -> Latex.text
   val isabelle_typewriter: Proof.context -> Latex.text -> Latex.text
   val typewriter: Proof.context -> string -> Latex.text
   val verbatim: Proof.context -> string -> Latex.text
   val source: Proof.context -> {embedded: bool} -> Token.src -> Latex.text
   val pretty: Proof.context -> Pretty.T -> Latex.text
   val pretty_source: Proof.context -> {embedded: bool} -> Token.src -> Pretty.T -> Latex.text
   val pretty_items: Proof.context -> Pretty.T list -> Latex.text
   val pretty_items_source: Proof.context -> {embedded: bool} -> Token.src ->
     Pretty.T list -> Latex.text
   val antiquotation_pretty:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Pretty.T) -> theory -> theory
   val antiquotation_pretty_embedded:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Pretty.T) -> theory -> theory
   val antiquotation_pretty_source:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Pretty.T) -> theory -> theory
   val antiquotation_pretty_source_embedded:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Pretty.T) -> theory -> theory
   val antiquotation_raw:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Latex.text) -> theory -> theory
   val antiquotation_raw_embedded:
     binding -> 'a context_parser -> (Proof.context -> 'a -> Latex.text) -> theory -> theory
   val antiquotation_verbatim:
     binding -> 'a context_parser -> (Proof.context -> 'a -> string) -> theory -> theory
   val antiquotation_verbatim_embedded:
     binding -> 'a context_parser -> (Proof.context -> 'a -> string) -> theory -> theory
 end;
 
 structure Document_Output: DOCUMENT_OUTPUT =
 struct
 
 (* output document source *)
 
 fun document_reports txt =
   let val pos = Input.pos_of txt in
     [(pos, Markup.language_document (Input.is_delimited txt)),
      (pos, Markup.plain_text)]
   end;
 
 fun output_comment ctxt (kind, syms) =
   (case kind of
     Comment.Comment =>
       Input.cartouche_content syms
       |> output_document (ctxt |> Config.put Document_Antiquotation.thy_output_display false)
           {markdown = false}
       |> Latex.enclose_text "%\n\\isamarkupcmt{" "%\n}"
   | Comment.Cancel =>
       Symbol_Pos.cartouche_content syms
       |> Latex.symbols_output
       |> Latex.enclose_text "%\n\\isamarkupcancel{" "}"
   | Comment.Latex => Latex.symbols (Symbol_Pos.cartouche_content syms)
   | Comment.Marker => [])
 and output_comment_document ctxt (comment, syms) =
   (case comment of
     SOME kind => output_comment ctxt (kind, syms)
   | NONE => Latex.symbols syms)
 and output_document_text ctxt syms =
   Comment.read_body syms |> maps (output_comment_document ctxt)
 and output_document ctxt {markdown} source =
   let
     val pos = Input.pos_of source;
     val syms = Input.source_explode source;
 
     val output_antiquotes =
       maps (Document_Antiquotation.evaluate (output_document_text ctxt) ctxt);
 
     fun output_line line =
       (if Markdown.line_is_item line then Latex.string "\\item " else []) @
         output_antiquotes (Markdown.line_content line);
 
     fun output_block (Markdown.Par lines) =
           separate (XML.Text "\n") (map (Latex.block o output_line) lines)
       | output_block (Markdown.List {kind, body, ...}) =
           Latex.environment_text (Markdown.print_kind kind) (output_blocks body)
     and output_blocks blocks =
       separate (XML.Text "\n\n") (map (Latex.block o output_block) blocks);
   in
     if Toplevel.is_skipped_proof (Toplevel.presentation_state ctxt) then []
     else if markdown andalso exists (Markdown.is_control o Symbol_Pos.symbol) syms
     then
       let
         val ants = Antiquote.parse_comments pos syms;
         val reports = Antiquote.antiq_reports ants;
         val blocks = Markdown.read_antiquotes ants;
         val _ = Context_Position.reports ctxt (reports @ Markdown.reports blocks);
       in output_blocks blocks end
     else
       let
         val ants = Antiquote.parse_comments pos (trim (Symbol.is_blank o Symbol_Pos.symbol) syms);
         val reports = Antiquote.antiq_reports ants;
         val _ = Context_Position.reports ctxt (reports @ Markdown.text_reports ants);
       in output_antiquotes ants end
   end;
 
 
 (* output tokens with formal comments *)
 
 local
 
 val output_symbols_antiq =
   (fn Antiquote.Text syms => Latex.symbols_output syms
     | Antiquote.Control {name = (name, _), body, ...} =>
         Latex.string (Latex.output_symbols [Symbol.encode (Symbol.Control name)]) @
           Latex.symbols_output body
     | Antiquote.Antiq {body, ...} =>
         Latex.enclose_text "%\n\\isaantiq\n" "{}%\n\\endisaantiq\n" (Latex.symbols_output body));
 
 fun output_comment_symbols ctxt {antiq} (comment, syms) =
   (case (comment, antiq) of
     (NONE, false) => Latex.symbols_output syms
   | (NONE, true) =>
       Antiquote.parse_comments (#1 (Symbol_Pos.range syms)) syms
       |> maps output_symbols_antiq
   | (SOME comment, _) => output_comment ctxt (comment, syms));
 
 fun output_body ctxt antiq bg en syms =
   Comment.read_body syms
   |> maps (output_comment_symbols ctxt {antiq = antiq})
   |> Latex.enclose_text bg en;
 
 in
 
 fun output_token ctxt tok =
   let
     fun output antiq bg en =
       output_body ctxt antiq bg en (Input.source_explode (Token.input_of tok));
   in
     (case Token.kind_of tok of
       Token.Comment NONE => []
     | Token.Comment (SOME Comment.Marker) => []
     | Token.Command => output false "\\isacommand{" "}"
     | Token.Keyword =>
         if Symbol.is_ascii_identifier (Token.content_of tok)
         then output false "\\isakeyword{" "}"
         else output false "" ""
     | Token.String => output false "{\\isachardoublequoteopen}" "{\\isachardoublequoteclose}"
     | Token.Alt_String => output false "{\\isacharbackquoteopen}" "{\\isacharbackquoteclose}"
     | Token.Verbatim => output true "{\\isacharverbatimopen}" "{\\isacharverbatimclose}"
     | Token.Cartouche => output false "{\\isacartoucheopen}" "{\\isacartoucheclose}"
     | Token.Control control => output_body ctxt false "" "" (Antiquote.control_symbols control)
     | _ => output false "" "")
   end handle ERROR msg => error (msg ^ Position.here (Token.pos_of tok));
 
 fun output_source ctxt s =
   output_body ctxt false "" "" (Symbol_Pos.explode (s, Position.none));
 
 fun check_comments ctxt =
   Comment.read_body #> List.app (fn (comment, syms) =>
     let
       val pos = #1 (Symbol_Pos.range syms);
       val _ =
         comment |> Option.app (fn kind =>
           Context_Position.reports ctxt (map (pair pos) (Comment.kind_markups kind)));
       val _ = output_comment_symbols ctxt {antiq = false} (comment, syms);
     in if comment = SOME Comment.Comment then check_comments ctxt syms else () end);
 
 end;
 
 
 
 (** present theory source **)
 
 (* presentation tokens *)
 
 datatype token =
     Ignore
   | Token of Token.T
   | Heading of string * Input.source
   | Body of string * Input.source
   | Raw of Input.source;
 
 fun token_with pred (Token tok) = pred tok
   | token_with _ _ = false;
 
 val white_token = token_with Document_Source.is_white;
 val white_comment_token = token_with Document_Source.is_white_comment;
 val blank_token = token_with Token.is_blank;
 val newline_token = token_with Token.is_newline;
 
 fun present_token ctxt tok =
   (case tok of
     Ignore => []
   | Token tok => output_token ctxt tok
   | Heading (cmd, source) =>
       Latex.enclose_text ("%\n\\isamarkup" ^ cmd ^ "{") "%\n}\n"
         (output_document ctxt {markdown = false} source)
   | Body (cmd, source) =>
       Latex.environment_text ("isamarkup" ^ cmd) (output_document ctxt {markdown = true} source)
   | Raw source =>
       Latex.string "%\n" @ output_document ctxt {markdown = true} source @ Latex.string "\n");
 
 
 (* command spans *)
 
-type command = string * Position.T;   (*name, position*)
-type source = (token * (string * int)) list;        (*token, markup flag, meta-comment depth*)
+type command = string * Position.T;  (*name, position*)
+type source = (token * (string * int)) list;  (*token, markup flag, meta-comment depth*)
 
 datatype span = Span of command * (source * source * source * source) * bool;
 
 fun make_span cmd src =
   let
     fun chop_newline (tok :: toks) =
           if newline_token (fst tok) then ([tok], toks, true)
           else ([], tok :: toks, false)
       | chop_newline [] = ([], [], false);
     val (((src_prefix, src_main), src_suffix1), (src_suffix2, src_appendix, newline)) =
       src
       |> chop_prefix (white_token o fst)
       ||>> chop_suffix (white_token o fst)
       ||>> chop_prefix (white_comment_token o fst)
       ||> chop_newline;
   in Span (cmd, (src_prefix, src_main, src_suffix1 @ src_suffix2, src_appendix), newline) end;
 
 
 (* present spans *)
 
 local
 
 fun err_bad_nesting here =
   error ("Bad nesting of commands in presentation" ^ here);
 
 fun edge which f (x: string option, y) =
   if x = y then I
   else (case which (x, y) of NONE => I | SOME txt => fold cons (Latex.string (f txt)));
 
 val begin_tag = edge #2 Latex.begin_tag;
 val end_tag = edge #1 Latex.end_tag;
 fun open_delim delim e = edge #2 Latex.begin_delim e #> delim #> edge #2 Latex.end_delim e;
 fun close_delim delim e = edge #1 Latex.begin_delim e #> delim #> edge #1 Latex.end_delim e;
 
 fun document_tag cmd_pos state state' tagging_stack =
   let
     val ctxt' = Toplevel.presentation_context state';
     val nesting = Toplevel.level state' - Toplevel.level state;
 
     val (tagging, taggings) = tagging_stack;
     val (tag', tagging') = Document_Source.update_tagging ctxt' tagging;
 
     val tagging_stack' =
       if nesting = 0 andalso not (Toplevel.is_proof state) then tagging_stack
       else if nesting >= 0 then (tagging', replicate nesting tagging @ taggings)
       else
         (case drop (~ nesting - 1) taggings of
           tg :: tgs => (tg, tgs)
         | [] => err_bad_nesting (Position.here cmd_pos));
   in (tag', tagging_stack') end;
 
 fun read_tag s =
   (case space_explode "%" s of
     ["", b] => (SOME b, NONE)
   | [a, b] => (NONE, SOME (a, b))
   | _ => error ("Bad document_tags specification: " ^ quote s));
 
 in
 
 fun make_command_tag options keywords =
   let
     val document_tags =
       map read_tag (space_explode "," (Options.string options \<^system_option>\<open>document_tags\<close>));
     val document_tags_default = map_filter #1 document_tags;
     val document_tags_command = map_filter #2 document_tags;
   in
     fn cmd_name => fn state => fn state' => fn active_tag =>
       let
         val keyword_tags =
           if cmd_name = "end" andalso Toplevel.is_end_theory state' then ["theory"]
           else Keyword.command_tags keywords cmd_name;
         val command_tags =
           the_list (AList.lookup (op =) document_tags_command cmd_name) @
           keyword_tags @ document_tags_default;
         val active_tag' =
           (case command_tags of
             default_tag :: _ => SOME default_tag
           | [] =>
               if Keyword.is_vacuous keywords cmd_name andalso Toplevel.is_proof state
               then active_tag
               else NONE);
       in active_tag' end
   end;
 
 fun present_span command_tag span state state'
     (tagging_stack, active_tag, newline, latex, present_cont) =
   let
     val ctxt' = Toplevel.presentation_context state';
     val present = fold (fn (tok, (flag, 0)) =>
         fold cons (present_token ctxt' tok)
         #> fold cons (Latex.string flag)
       | _ => I);
 
     val Span ((cmd_name, cmd_pos), srcs, span_newline) = span;
 
     val (tag', tagging_stack') = document_tag cmd_pos state state' tagging_stack;
     val active_tag' =
       if is_some tag' then Option.map #1 tag'
       else command_tag cmd_name state state' active_tag;
     val edge = (active_tag, active_tag');
 
     val newline' =
       if is_none active_tag' then span_newline else newline;
 
     val latex' =
       latex
       |> end_tag edge
       |> close_delim (fst present_cont) edge
       |> snd present_cont
       |> open_delim (present (#1 srcs)) edge
       |> begin_tag edge
       |> present (#2 srcs);
     val present_cont' =
       if newline then (present (#3 srcs), present (#4 srcs))
       else (I, present (#3 srcs) #> present (#4 srcs));
   in (tagging_stack', active_tag', newline', latex', present_cont') end;
 
 fun present_trailer ((_, tags), active_tag, _, latex, present_cont) =
   if not (null tags) then err_bad_nesting " at end of theory"
   else
     latex
     |> end_tag (active_tag, NONE)
     |> close_delim (fst present_cont) (active_tag, NONE)
     |> snd present_cont;
 
 end;
 
 
 (* present_thy *)
 
 local
 
 val markup_true = "\\isamarkuptrue%\n";
 val markup_false = "\\isamarkupfalse%\n";
 
 val opt_newline = Scan.option (Scan.one Token.is_newline);
 
 val ignore =
   Scan.depend (fn d => opt_newline |-- Scan.one Token.is_begin_ignore
     >> pair (d + 1)) ||
   Scan.depend (fn d => Scan.one Token.is_end_ignore --|
     (if d = 0 then Scan.fail_with (K (fn () => "Bad nesting of meta-comments")) else opt_newline)
     >> pair (d - 1));
 
 val locale =
   Scan.option ((Parse.$$$ "(" -- Document_Source.improper -- Parse.$$$ "in") |--
     Parse.!!!
       (Document_Source.improper |-- Parse.name --| (Document_Source.improper -- Parse.$$$ ")")));
 
 in
 
 type segment =
   {span: Command_Span.span, command: Toplevel.transition,
    prev_state: Toplevel.state, state: Toplevel.state};
 
 fun present_thy options thy (segments: segment list) =
   let
     val keywords = Thy_Header.get_keywords thy;
 
 
     (* tokens *)
 
     val ignored = Scan.state --| ignore
       >> (fn d => (NONE, (Ignore, ("", d))));
 
     fun markup pred mk flag = Scan.peek (fn d =>
       Document_Source.improper |--
         Parse.position (Scan.one (fn tok =>
           Token.is_command tok andalso pred keywords (Token.content_of tok))) --
       (Document_Source.annotation |--
         Parse.!!!! ((Document_Source.improper -- locale -- Document_Source.improper) |--
           Parse.document_source --| Document_Source.improper_end))
             >> (fn ((tok, pos'), source) =>
               let val name = Token.content_of tok
               in (SOME (name, pos'), (mk (name, source), (flag, d))) end));
 
     val command = Scan.peek (fn d =>
       Scan.optional (Scan.one Token.is_command_modifier ::: Document_Source.improper) [] --
       Scan.one Token.is_command --| Document_Source.annotation
       >> (fn (cmd_mod, cmd) =>
         map (fn tok => (NONE, (Token tok, ("", d)))) cmd_mod @
           [(SOME (Token.content_of cmd, Token.pos_of cmd),
             (Token cmd, (markup_false, d)))]));
 
     val cmt = Scan.peek (fn d =>
       Scan.one Document_Source.is_black_comment >> (fn tok => (NONE, (Token tok, ("", d)))));
 
     val other = Scan.peek (fn d =>
        Parse.not_eof >> (fn tok => (NONE, (Token tok, ("", d)))));
 
     val tokens =
       (ignored ||
         markup Keyword.is_document_heading Heading markup_true ||
         markup Keyword.is_document_body Body markup_true ||
         markup Keyword.is_document_raw (Raw o #2) "") >> single ||
       command ||
       (cmt || other) >> single;
 
 
     (* spans *)
 
     val is_eof = fn (_, (Token x, _)) => Token.is_eof x | _ => false;
     val stopper = Scan.stopper (K (NONE, (Token Token.eof, ("", 0)))) is_eof;
 
     val cmd = Scan.one (is_some o fst);
     val non_cmd = Scan.one (is_none o fst andf not o is_eof) >> #2;
 
     val white_comments = Scan.many (white_comment_token o fst o snd);
     val blank = Scan.one (blank_token o fst o snd);
     val newline = Scan.one (newline_token o fst o snd);
     val before_cmd =
       Scan.option (newline -- white_comments) --
       Scan.option (newline -- white_comments) --
       Scan.option (blank -- white_comments) -- cmd;
 
     val span =
       Scan.repeat non_cmd -- cmd --
         Scan.repeat (Scan.unless before_cmd non_cmd) --
         Scan.option (newline >> (single o snd))
       >> (fn (((toks1, (cmd, tok2)), toks3), tok4) =>
           make_span (the cmd) (toks1 @ (tok2 :: (toks3 @ the_default [] tok4))));
 
     val spans = segments
       |> maps (Command_Span.content o #span)
       |> drop_suffix Token.is_space
       |> Source.of_list
       |> Source.source' 0 Token.stopper (Scan.error (Scan.bulk tokens >> flat))
       |> Source.source stopper (Scan.error (Scan.bulk span))
       |> Source.exhaust;
 
     val command_results =
       segments |> map_filter (fn {command, state, ...} =>
         if Toplevel.is_ignored command then NONE else SOME (command, state));
 
 
     (* present commands *)
 
     val command_tag = make_command_tag options keywords;
 
     fun present_command tr span st st' =
       Toplevel.setmp_thread_position tr (present_span command_tag span st st');
 
     fun present _ [] = I
       | present st ((span, (tr, st')) :: rest) = present_command tr span st st' #> present st' rest;
   in
     if length command_results = length spans then
       (([], []), NONE, true, [], (I, I))
       |> present (Toplevel.init_toplevel ()) (spans ~~ command_results)
       |> present_trailer
       |> rev
     else error "Messed-up outer syntax for presentation"
   end;
 
 end;
 
 
 
 (** standard output operations **)
 
 (* pretty printing *)
 
 fun pretty_term ctxt t =
   Syntax.pretty_term (Proof_Context.augment t ctxt) t;
 
 fun pretty_thm ctxt = pretty_term ctxt o Thm.full_prop_of;
 
 
 (* default output *)
 
 fun isabelle ctxt body =
   if Config.get ctxt Document_Antiquotation.thy_output_display
   then Latex.environment_text "isabelle" body
   else Latex.enclose_text "\\isa{" "}" body;
 
 fun isabelle_typewriter ctxt body =
   if Config.get ctxt Document_Antiquotation.thy_output_display
   then Latex.environment_text "isabellett" body
   else Latex.enclose_text "\\isatt{" "}" body;
 
 fun typewriter ctxt s =
   isabelle_typewriter ctxt (Latex.string (Latex.output_ascii s));
 
 fun verbatim ctxt =
   if Config.get ctxt Document_Antiquotation.thy_output_display
   then Document_Antiquotation.indent_lines ctxt #> typewriter ctxt
   else split_lines #> map (typewriter ctxt #> Latex.block) #> separate (XML.Text "\\isanewline%\n");
 
 fun token_source ctxt {embedded} tok =
   if Token.is_kind Token.Cartouche tok andalso embedded andalso
     not (Config.get ctxt Document_Antiquotation.thy_output_source_cartouche)
   then Token.content_of tok
   else Token.unparse tok;
 
 fun is_source ctxt =
   Config.get ctxt Document_Antiquotation.thy_output_source orelse
   Config.get ctxt Document_Antiquotation.thy_output_source_cartouche;
 
 fun source ctxt embedded =
   Token.args_of_src
   #> map (token_source ctxt embedded #> Document_Antiquotation.prepare_lines ctxt)
   #> space_implode " "
   #> output_source ctxt
   #> isabelle ctxt;
 
 fun pretty ctxt =
   Document_Antiquotation.output ctxt #> Latex.string #> isabelle ctxt;
 
 fun pretty_source ctxt embedded src prt =
   if is_source ctxt then source ctxt embedded src else pretty ctxt prt;
 
 fun pretty_items ctxt =
   map (Document_Antiquotation.output ctxt #> XML.Text) #>
   separate (XML.Text "\\isasep\\isanewline%\n") #> isabelle ctxt;
 
 fun pretty_items_source ctxt embedded src prts =
   if is_source ctxt then source ctxt embedded src else pretty_items ctxt prts;
 
 
 (* antiquotation variants *)
 
 local
 
 fun gen_setup name embedded =
   if embedded
   then Document_Antiquotation.setup_embedded name
   else Document_Antiquotation.setup name;
 
 fun gen_antiquotation_pretty name embedded scan f =
   gen_setup name embedded scan (fn {context = ctxt, argument = x, ...} => pretty ctxt (f ctxt x));
 
 fun gen_antiquotation_pretty_source name embedded scan f =
   gen_setup name embedded scan
     (fn {context = ctxt, source = src, argument = x} =>
       pretty_source ctxt {embedded = embedded} src (f ctxt x));
 
 fun gen_antiquotation_raw name embedded scan f =
   gen_setup name embedded scan (fn {context = ctxt, argument = x, ...} => f ctxt x);
 
 fun gen_antiquotation_verbatim name embedded scan f =
   gen_antiquotation_raw name embedded scan (fn ctxt => verbatim ctxt o f ctxt);
 
 in
 
 fun antiquotation_pretty name = gen_antiquotation_pretty name false;
 fun antiquotation_pretty_embedded name = gen_antiquotation_pretty name true;
 
 fun antiquotation_pretty_source name = gen_antiquotation_pretty_source name false;
 fun antiquotation_pretty_source_embedded name = gen_antiquotation_pretty_source name true;
 
 fun antiquotation_raw name = gen_antiquotation_raw name false;
 fun antiquotation_raw_embedded name = gen_antiquotation_raw name true;
 
 fun antiquotation_verbatim name = gen_antiquotation_verbatim name false;
 fun antiquotation_verbatim_embedded name = gen_antiquotation_verbatim name true;
 
 end;
 
 end;