diff --git a/src/Doc/System/Presentation.thy b/src/Doc/System/Presentation.thy
--- a/src/Doc/System/Presentation.thy
+++ b/src/Doc/System/Presentation.thy
@@ -1,203 +1,202 @@
 (*:maxLineLen=78:*)
 
 theory Presentation
 imports Base
 begin
 
 chapter \<open>Presenting theories \label{ch:present}\<close>
 
 text \<open>
   Isabelle provides several ways to present the outcome of formal
   developments, including WWW-based browsable libraries or actual printable
   documents. Presentation is centered around the concept of \<^emph>\<open>sessions\<close>
   (\chref{ch:session}). The global session structure is that of a tree, with
   Isabelle Pure at its root, further object-logics derived (e.g.\ HOLCF from
   HOL, and HOL from Pure), and application sessions further on in the
   hierarchy.
 
   The command-line tools @{tool_ref mkroot} and @{tool_ref build} provide the
   primary means for managing Isabelle sessions, including options for
   presentation: ``\<^verbatim>\<open>document=pdf\<close>'' generates PDF output from the theory
   session, and ``\<^verbatim>\<open>document_output=dir\<close>'' emits a copy of the document sources
   with the PDF into the given directory (relative to the session directory).
 
   Alternatively, @{tool_ref document} may be used to turn the generated
   {\LaTeX} sources of a session (exports from its build database) into PDF.
 \<close>
 
 
 section \<open>Generating HTML browser information \label{sec:info}\<close>
 
 text \<open>
   As a side-effect of building sessions, Isabelle is able to generate theory
   browsing information, including HTML documents that show the theory sources
   and the relationship with its ancestors and descendants. Besides the HTML
   file that is generated for every theory, Isabelle stores links to all
   theories of a session in an index file. As a second hierarchy, groups of
   sessions are organized as \<^emph>\<open>chapters\<close>, with a separate index. Note that the
   implicit tree structure of the session build hierarchy is \<^emph>\<open>not\<close> relevant
   for the presentation.
 
   \<^medskip>
   To generate theory browsing information for an existing session, just invoke
   @{tool build} with suitable options:
   @{verbatim [display] \<open>isabelle build -o browser_info -v -c FOL\<close>}
 
   The presentation output will appear in a sub-directory
   \<^path>\<open>$ISABELLE_BROWSER_INFO\<close>, according to the chapter and session name.
 
   Many Isabelle sessions (such as \<^session>\<open>HOL-Library\<close> in
   \<^dir>\<open>~~/src/HOL/Library\<close>) also provide theory documents in PDF. These are
   prepared automatically as well if enabled like this:
   @{verbatim [display] \<open>isabelle build -o browser_info -o document -v -c HOL-Library\<close>}
 
   Enabling both browser info and document preparation simultaneously causes an
   appropriate ``document'' link to be included in the HTML index. Documents
   may be generated independently of browser information as well, see
   \secref{sec:tool-document} for further details.
 
   \<^bigskip>
   The theory browsing information is stored in the directory determined by the
   @{setting_ref ISABELLE_BROWSER_INFO} setting, with sub-directory structure
   according to the chapter and session name. In order to present Isabelle
   applications on the web, the corresponding subdirectory from @{setting
   ISABELLE_BROWSER_INFO} can be put on a WWW server.
 \<close>
 
 
 section \<open>Preparing session root directories \label{sec:tool-mkroot}\<close>
 
 text \<open>
   The @{tool_def mkroot} tool configures a given directory as session root,
   with some \<^verbatim>\<open>ROOT\<close> file and optional document source directory. Its usage is:
   @{verbatim [display]
 \<open>Usage: isabelle mkroot [OPTIONS] [DIRECTORY]
 
   Options are:
     -A LATEX     provide author in LaTeX notation (default: user name)
     -I           init Mercurial repository and add generated files
     -T LATEX     provide title in LaTeX notation (default: session name)
     -n NAME      alternative session name (default: directory base name)
 
   Prepare session root directory (default: current directory).
 \<close>}
 
   The results are placed in the given directory \<open>dir\<close>, which refers to the
   current directory by default. The @{tool mkroot} tool is conservative in the
   sense that it does not overwrite existing files or directories. Earlier
   attempts to generate a session root need to be deleted manually.
 
   The generated session template will be accompanied by a formal document,
   with \<open>DIRECTORY\<close>\<^verbatim>\<open>/document/root.tex\<close> as its {\LaTeX} entry point (see also
   \chref{ch:present}).
 
   Options \<^verbatim>\<open>-T\<close> and \<^verbatim>\<open>-A\<close> specify the document title and author explicitly,
   using {\LaTeX} source notation.
 
   Option \<^verbatim>\<open>-I\<close> initializes a Mercurial repository in the target directory, and
   adds all generated files (without commit).
 
   Option \<^verbatim>\<open>-n\<close> specifies an alternative session name; otherwise the base name
   of the given directory is used.
 
   \<^medskip>
   The implicit Isabelle settings variable @{setting ISABELLE_LOGIC} specifies
   the parent session.
 \<close>
 
 
 subsubsection \<open>Examples\<close>
 
 text \<open>
   Produce session \<^verbatim>\<open>Test\<close> within a separate directory of the same name:
   @{verbatim [display] \<open>isabelle mkroot Test && isabelle build -D Test\<close>}
 
   \<^medskip>
   Upgrade the current directory into a session ROOT with document preparation,
   and build it:
   @{verbatim [display] \<open>isabelle mkroot && isabelle build -D .\<close>}
 \<close>
 
 
 section \<open>Preparing Isabelle session documents \label{sec:tool-document}\<close>
 
 text \<open>
   The @{tool_def document} tool prepares logic session documents. Its usage
   is:
   @{verbatim [display]
 \<open>Usage: isabelle document [OPTIONS] SESSION
 
   Options are:
     -O DIR       output directory for LaTeX sources and resulting PDF
     -P DIR       output directory for resulting PDF
     -S DIR       output directory for LaTeX sources
     -V           verbose latex
     -d DIR       include session directory
     -o OPTION    override Isabelle system OPTION (via NAME=VAL or NAME)
     -v           verbose build
 
   Prepare the theory document of a session.\<close>}
 
   Generated {\LaTeX} sources are taken from the session build database:
   @{tool_ref build} is invoked beforehand to ensure that it is up-to-date.
   Further files are generated on the spot, notably essential Isabelle style
   files, and \<^verbatim>\<open>session.tex\<close> to input all theory sources from the session
   (excluding imports from other sessions).
 
   \<^medskip> Options \<^verbatim>\<open>-d\<close>, \<^verbatim>\<open>-o\<close>, \<^verbatim>\<open>-v\<close> have the same meaning as for @{tool
   build}.
 
   \<^medskip> Option \<^verbatim>\<open>-V\<close> prints full output of {\LaTeX} tools.
 
   \<^medskip> Option \<^verbatim>\<open>-O\<close>~\<open>dir\<close> specifies the output directory for generated {\LaTeX}
   sources and the result PDF file. Options \<^verbatim>\<open>-P\<close> and \<^verbatim>\<open>-S\<close> only refer to the
   PDF and sources, respectively.
 
   For example, for output directory ``\<^verbatim>\<open>output\<close>'' and the default document
   variant ``\<^verbatim>\<open>document\<close>'', the generated document sources are placed into the
   subdirectory \<^verbatim>\<open>output/document/\<close> and the resulting PDF into
   \<^verbatim>\<open>output/document.pdf\<close>.
 
   \<^medskip> Isabelle is usually smart enough to create the PDF from the given
   \<^verbatim>\<open>root.tex\<close> and optional \<^verbatim>\<open>root.bib\<close> (bibliography) and \<^verbatim>\<open>root.idx\<close> (index)
   using standard {\LaTeX} tools. Actual command-lines are given by settings
   @{setting_ref ISABELLE_LUALATEX} (or @{setting_ref ISABELLE_PDFLATEX}),
   @{setting_ref ISABELLE_BIBTEX}, @{setting_ref ISABELLE_MAKEINDEX}: these
   variables are used without quoting in shell scripts, and thus may contain
   additional options.
 
   The system option @{system_option_def "document_build"} specifies an
   alternative build engine, e.g. within the session \<^verbatim>\<open>ROOT\<close> file as
   ``\<^verbatim>\<open>options [document_build = pdflatex]\<close>''. The following standard engines
   are available:
 
     \<^item> \<^verbatim>\<open>lualatex\<close> (default) uses the shell command \<^verbatim>\<open>$ISABELLE_LUALATEX\<close> on
     the main \<^verbatim>\<open>root.tex\<close> file, with further runs of \<^verbatim>\<open>$ISABELLE_BIBTEX\<close> and
     \<^verbatim>\<open>$ISABELLE_MAKEINDEX\<close> as required.
 
     \<^item> \<^verbatim>\<open>pdflatex\<close> uses \<^verbatim>\<open>$ISABELLE_PDFLATEX\<close> instead of \<^verbatim>\<open>$ISABELLE_LUALATEX\<close>,
     and the other tools as above.
 
     \<^item> \<^verbatim>\<open>build\<close> invokes an executable script of the same name in a private
     directory containing all \isakeyword{document\_files} and other generated
     document sources. The script is invoked as ``\<^verbatim>\<open>./build pdf\<close>~\<open>name\<close>'' for
     the document variant name; it needs to produce a corresponding
     \<open>name\<close>\<^verbatim>\<open>.pdf\<close> file by arbitrary means on its own.
 
   Further engines can be defined by add-on components in Isabelle/Scala
   (\secref{sec:scala-build}), providing a service class derived from
-  \<^scala_type>\<open>isabelle.Document_Build.Engine\<close>. Available classes are listed
-  in \<^scala>\<open>isabelle.Document_Build.engines\<close>.
+  \<^scala_type>\<open>isabelle.Document_Build.Engine\<close>.
 \<close>
 
 
 subsubsection \<open>Examples\<close>
 
 text \<open>
   Produce the document from session \<^verbatim>\<open>FOL\<close> with full verbosity, and a copy in
   the current directory (subdirectory \<^verbatim>\<open>document\<close> and file \<^verbatim>\<open>document.pdf)\<close>:
 
   @{verbatim [display] \<open>isabelle document -v -V -O. FOL\<close>}
 \<close>
 
 end