doc-src/TutorialI/Documents/Documents.thy

 (*>*)
 
 section {* Concrete Syntax \label{sec:concrete-syntax} *}
 
 text {*
-  The core concept of Isabelle's framework for concrete
-  syntax is that of \bfindex{mixfix annotations}.  Associated
-  with any kind of constant declaration, mixfixes affect both the
-  grammar productions for the parser and output templates for the
-  pretty printer.
+  The core concept of Isabelle's framework for concrete syntax is that
+  of \bfindex{mixfix annotations}.  Associated with any kind of
+  constant declaration, mixfixes affect both the grammar productions
+  for the parser and output templates for the pretty printer.
 
   In full generality, parser and pretty printer configuration is a
-  subtle affair \cite{isabelle-ref}.  Your syntax
-  specifications need to interact properly with the
-  existing setup of Isabelle/Pure and Isabelle/HOL\@.  
-  To avoid creating ambiguities with existing elements, it is
-  particularly important to give new syntactic
+  subtle affair \cite{isabelle-ref}.  Your syntax specifications need
+  to interact properly with the existing setup of Isabelle/Pure and
+  Isabelle/HOL\@.  To avoid creating ambiguities with existing
+  elements, it is particularly important to give new syntactic
   constructs the right precedence.
 
   \medskip Subsequently we introduce a few simple syntax declaration
   forms that already cover many common situations fairly well.
 *}

 
 subsection {* Infix Annotations *}
 
 text {*
   Syntax annotations may be included wherever constants are declared,
-  such as \isacommand{consts} and
-  \isacommand{constdefs} --- and also \isacommand{datatype}, which
-  declares constructor operations.  Type-constructors may be annotated as
-  well, although this is less frequently encountered in practice (the
-  infix type @{text "\<times>"} comes to mind).
+  such as \isacommand{consts} and \isacommand{constdefs} --- and also
+  \isacommand{datatype}, which declares constructor operations.
+  Type-constructors may be annotated as well, although this is less
+  frequently encountered in practice (the infix type @{text "\<times>"} comes
+  to mind).
 
   Infix declarations\index{infix annotations} provide a useful special
-  case of mixfixes.  The following example of the
-  exclusive-or operation on boolean values illustrates typical infix
-  declarations.
+  case of mixfixes.  The following example of the exclusive-or
+  operation on boolean values illustrates typical infix declarations.
 *}
 
 constdefs
   xor :: "bool \<Rightarrow> bool \<Rightarrow> bool"    (infixl "[+]" 60)
   "A [+] B \<equiv> (A \<and> \<not> B) \<or> (\<not> A \<and> B)"
 
 text {*
   \noindent Now @{text "xor A B"} and @{text "A [+] B"} refer to the
   same expression internally.  Any curried function with at least two
-  arguments may be given infix syntax.  For partial
-  applications with fewer than two operands, there is a notation
-  using the prefix~\isa{op}.  For instance, @{text xor} without arguments is represented
-  as @{text "op [+]"}; together with ordinary function application, this
+  arguments may be given infix syntax.  For partial applications with
+  fewer than two operands, there is a notation using the prefix~@{text
+  op}.  For instance, @{text xor} without arguments is represented as
+  @{text "op [+]"}; together with ordinary function application, this
   turns @{text "xor A"} into @{text "op [+] A"}.
 
   \medskip The keyword \isakeyword{infixl} seen above specifies an
   infix operator that is nested to the \emph{left}: in iterated
   applications the more complex expression appears on the left-hand
-  side, and @{term "A [+] B [+] C"} stands for @{text "(A [+] B) [+] C"}.
-  Similarly, \isakeyword{infixr} specifies nesting to the
+  side, and @{term "A [+] B [+] C"} stands for @{text "(A [+] B) [+]
+  C"}.  Similarly, \isakeyword{infixr} means nesting to the
   \emph{right}, reading @{term "A [+] B [+] C"} as @{text "A [+] (B
-  [+] C)"}.  In contrast, a \emph{non-oriented} declaration via
-  \isakeyword{infix} would render @{term "A [+] B [+] C"} illegal, but
-  demand explicit parentheses to indicate the intended grouping.
+  [+] C)"}.  A \emph{non-oriented} declaration via \isakeyword{infix}
+  would render @{term "A [+] B [+] C"} illegal, but demand explicit
+  parentheses to indicate the intended grouping.
 
   The string @{text [source] "[+]"} in our annotation refers to the
   concrete syntax to represent the operator (a literal token), while
   the number @{text 60} determines the precedence of the construct:
-  the syntactic priorities of the arguments and result.
-  Isabelle/HOL already uses up many popular combinations of
-  ASCII symbols for its own use, including both @{text "+"} and @{text
-  "++"}.  Longer character combinations are
-  more likely to be still available for user extensions, such as our~@{text "[+]"}.
-
-  Operator precedences have a range of 0--1000.  Very low or high priorities are
-  reserved for the meta-logic.  HOL syntax
-  mainly uses the range of 10--100: the equality infix @{text "="} is
-  centered at 50; logical connectives (like @{text "\<or>"} and @{text
-  "\<and>"}) are below 50; algebraic ones (like @{text "+"} and @{text
-  "*"}) are above 50.  User syntax should strive to coexist with common
-  HOL forms, or use the mostly unused range 100--900.
-
+  the syntactic priorities of the arguments and result.  Isabelle/HOL
+  already uses up many popular combinations of ASCII symbols for its
+  own use, including both @{text "+"} and @{text "++"}.  Longer
+  character combinations are more likely to be still available for
+  user extensions, such as our~@{text "[+]"}.
+
+  Operator precedences have a range of 0--1000.  Very low or high
+  priorities are reserved for the meta-logic.  HOL syntax mainly uses
+  the range of 10--100: the equality infix @{text "="} is centered at
+  50; logical connectives (like @{text "\<or>"} and @{text "\<and>"}) are
+  below 50; algebraic ones (like @{text "+"} and @{text "*"}) are
+  above 50.  User syntax should strive to coexist with common HOL
+  forms, or use the mostly unused range 100--900.
 *}
 
 
 subsection {* Mathematical Symbols \label{sec:syntax-symbols} *}
 
 text {*
-  Concrete syntax based on ASCII characters has inherent
-  limitations.  Mathematical notation demands a larger repertoire
-  of glyphs.  Several standards of extended character sets have been
-  proposed over decades, but none has become universally available so
-  far.  Isabelle supports a generic notion of \bfindex{symbols} as the
-  smallest entities of source text, without referring to internal
-  encodings.  There are three kinds of such ``generalized
-  characters'':
+  Concrete syntax based on ASCII characters has inherent limitations.
+  Mathematical notation demands a larger repertoire of glyphs.
+  Several standards of extended character sets have been proposed over
+  decades, but none has become universally available so far.  Isabelle
+  has its own notion of \bfindex{symbols} as the smallest entities of
+  source text, without referring to internal encodings.  There are
+  three kinds of such ``generalized characters'':
 
   \begin{enumerate}
 
   \item 7-bit ASCII characters
 

 
   \end{enumerate}
 
   Here $ident$ may be any identifier according to the usual Isabelle
   conventions.  This results in an infinite store of symbols, whose
-  interpretation is left to further front-end tools.  For example,
-  both the user-interface of Proof~General + X-Symbol and the Isabelle
-  document processor (see \S\ref{sec:document-preparation}) display
-  the \verb,\,\verb,<forall>, symbol as~@{text \<forall>}.
+  interpretation is left to further front-end tools.  For example, the
+  user-interface of Proof~General + X-Symbol and the Isabelle document
+  processor (see \S\ref{sec:document-preparation}) display the
+  \verb,\,\verb,<forall>, symbol as~@{text \<forall>}.
 
   A list of standard Isabelle symbols is given in
-  \cite[appendix~A]{isabelle-sys}.  You may introduce their own
+  \cite[appendix~A]{isabelle-sys}.  You may introduce your own
   interpretation of further symbols by configuring the appropriate
   front-end tool accordingly, e.g.\ by defining certain {\LaTeX}
   macros (see also \S\ref{sec:doc-prep-symbols}).  There are also a
   few predefined control symbols, such as \verb,\,\verb,<^sub>, and
   \verb,\,\verb,<^sup>, for sub- and superscript of the subsequent
   printable symbol, respectively.  For example, \verb,A\<^sup>\<star>, is
   output as @{text "A\<^sup>\<star>"}.
 
-  \medskip Replacing our definition of @{text xor} by the following 
+  \medskip Replacing our definition of @{text xor} by the following
   specifies a Isabelle symbol for the new operator:
 *}
 
 (*<*)
 hide const xor

 (*>*)
 
 text {*
   \noindent The X-Symbol package within Proof~General provides several
   input methods to enter @{text \<oplus>} in the text.  If all fails one may
-  just type a named entity \verb,\,\verb,<oplus>, by hand; the 
-  corresponding symbol will immediately be displayed.
-
-  \medskip More flexible is to provide alternative
-  syntax forms through the \bfindex{print mode} concept~\cite{isabelle-ref}.  
-  By convention, the mode of
-  ``$xsymbols$'' is enabled whenever Proof~General's X-Symbol mode or
-  {\LaTeX} output is active.  Now consider the following hybrid
-  declaration of @{text xor}:
+  just type a named entity \verb,\,\verb,<oplus>, by hand; the
+  corresponding symbol will be displayed after further input.
+
+  \medskip More flexible is to provide alternative syntax forms
+  through the \bfindex{print mode} concept~\cite{isabelle-ref}.  By
+  convention, the mode of ``$xsymbols$'' is enabled whenever
+  Proof~General's X-Symbol mode or {\LaTeX} output is active.  Now
+  consider the following hybrid declaration of @{text xor}:
 *}
 
 (*<*)
 hide const xor
 ML_setup {* Context.>> (Theory.add_path "version2") *}

   "(xsymbols)"}, is optional.  Also note that its type merely serves
   for syntactic purposes, and is \emph{not} checked for consistency
   with the real constant.
 
   \medskip We may now write @{text "A [+] B"} or @{text "A \<oplus> B"} in
-  input, while output uses the nicer syntax of $xsymbols$, provided
+  input, while output uses the nicer syntax of $xsymbols$ whenever
   that print mode is active.  Such an arrangement is particularly
-  useful for interactive development, where users may type ASCII
-  text and see mathematical symbols displayed during proofs.
+  useful for interactive development, where users may type ASCII text
+  and see mathematical symbols displayed during proofs.
 *}
 
 
 subsection {* Prefix Annotations *}
 
 text {*
-  Prefix syntax annotations\index{prefix annotation} are another
-  form of mixfixes \cite{isabelle-ref}, without any
-  template arguments or priorities --- just some bits of literal
-  syntax.  The following example illustrates this idea idea by
-  associating common symbols with the constructors of a datatype.
+  Prefix syntax annotations\index{prefix annotation} are another form
+  of mixfixes \cite{isabelle-ref}, without any template arguments or
+  priorities --- just some literal syntax.  The following example
+  associates common symbols with the constructors of a datatype.
 *}
 
 datatype currency =
     Euro nat    ("\<euro>")
   | Pounds nat  ("\<pounds>")

   printed as @{term "\<euro> 10"}; only the head of the application is
   subject to our concrete syntax.  This rather simple form already
   achieves conformance with notational standards of the European
   Commission.
 
-  Prefix syntax also works for \isakeyword{consts} or
+  Prefix syntax works the same way for \isakeyword{consts} or
   \isakeyword{constdefs}.
 *}
 
 
 subsection {* Syntax Translations \label{sec:syntax-translations} *}
 
 text{*
-  Mixfix syntax annotations merely decorate
-  particular constant application forms with
-  concrete syntax, for instance replacing \ @{text "xor A B"} by @{text "A \<oplus> B"}.  Occasionally, the relationship between some piece of
-  notation and its internal form is more complicated.  Here we need
-  \bfindex{syntax translations}.
+  Mixfix syntax annotations merely decorate particular constant
+  application forms with concrete syntax, for instance replacing \
+  @{text "xor A B"} by @{text "A \<oplus> B"}.  Occasionally, the
+  relationship between some piece of notation and its internal form is
+  more complicated.  Here we need \bfindex{syntax translations}.
 
   Using the \isakeyword{syntax}\index{syntax (command)}, command we
   introduce uninterpreted notational elements.  Then
   \commdx{translations} relate input forms to complex logical
-  expressions.  This provides a simple mechanism for
-  syntactic macros; even heavier transformations may be written in ML
+  expressions.  This provides a simple mechanism for syntactic macros;
+  even heavier transformations may be written in ML
   \cite{isabelle-ref}.
 
   \medskip A typical use of syntax translations is to introduce
-  relational notation for membership in a set of pair, 
-  replacing \ @{text "(x, y) \<in> sim"} by @{text "x \<approx> y"}.
+  relational notation for membership in a set of pair, replacing \
+  @{text "(x, y) \<in> sim"} by @{text "x \<approx> y"}.
 *}
 
 consts
   sim :: "('a \<times> 'a) set"
 

 translations
   "x \<approx> y" \<rightleftharpoons> "(x, y) \<in> sim"
 
 text {*
   \noindent Here the name of the dummy constant @{text "_sim"} does
-  not matter, as long as it is not used elsewhere.  Prefixing
-  an underscore is a common convention.  The \isakeyword{translations}
+  not matter, as long as it is not used elsewhere.  Prefixing an
+  underscore is a common convention.  The \isakeyword{translations}
   declaration already uses concrete syntax on the left-hand side;
   internally we relate a raw application @{text "_sim x y"} with
   @{text "(x, y) \<in> sim"}.
 
   \medskip Another common application of syntax translations is to

   instead of \isakeyword{syntax} + \isakeyword{translations}.  The
   present formulation has the virtue that expressions are immediately
   replaced by the ``definition'' upon parsing; the effect is reversed
   upon printing.
 
-  This sort of translation is appropriate when the 
-  defined concept is a trivial variation on an
-  existing one.  On the other hand, syntax translations do not scale
-  up well to large hierarchies of concepts.  Translations
-  do not replace definitions!
+  This sort of translation is appropriate when the defined concept is
+  a trivial variation on an existing one.  On the other hand, syntax
+  translations do not scale up well to large hierarchies of concepts.
+  Translations do not replace definitions!
 *}
 
 
 section {* Document Preparation \label{sec:document-preparation} *}
 
 text {*
   Isabelle/Isar is centered around the concept of \bfindex{formal
-  proof documents}\index{documents|bold}.  The outcome of a
-  formal development effort is meant to be a human-readable record,
-  presented as browsable PDF file or printed on paper.  The overall
-  document structure follows traditional mathematical articles, with
-  sections, intermediate explanations, definitions, theorems and
-  proofs.
+  proof documents}\index{documents|bold}.  The outcome of a formal
+  development effort is meant to be a human-readable record, presented
+  as browsable PDF file or printed on paper.  The overall document
+  structure follows traditional mathematical articles, with sections,
+  intermediate explanations, definitions, theorems and proofs.
 
   \medskip The Isabelle document preparation system essentially acts
   as a front-end to {\LaTeX}.  After checking specifications and
   proofs formally, the theory sources are turned into typesetting
-  instructions in a schematic manner.  This lets you write
-  authentic reports on theory developments with little effort: many
-  technical consistency checks are handled by the system.
+  instructions in a schematic manner.  This lets you write authentic
+  reports on theory developments with little effort: many technical
+  consistency checks are handled by the system.
 
   Here is an example to illustrate the idea of Isabelle document
   preparation.
 *}
 

 *}
 
 text_raw {* \end{quotation} *}
 
 text {*
-  The above document output has been produced by the following theory
-  specification:
+  \noindent The above document output has been produced as follows:
 
   \begin{ttbox}
   text {\ttlbrace}*
     The following datatype definition of {\at}{\ttlbrace}text "'a bintree"{\ttrbrace}
     models binary trees with nodes being decorated by elements
     of type {\at}{\ttlbrace}typ 'a{\ttrbrace}.
   *{\ttrbrace}
 
   datatype 'a bintree =
     Leaf | Branch 'a  "'a bintree"  "'a bintree"
-
+  \end{ttbox}
+  \begin{ttbox}
   text {\ttlbrace}*
     {\ttback}noindent The datatype induction rule generated here is
     of the form {\at}{\ttlbrace}thm [display] bintree.induct [no_vars]{\ttrbrace}
   *{\ttrbrace}
-  \end{ttbox}
+  \end{ttbox}\vspace{-\medskipamount}
 
   \noindent Here we have augmented the theory by formal comments
-  (using \isakeyword{text} blocks).  The informal parts may again
-  refer to formal entities by means of ``antiquotations'' (such as
+  (using \isakeyword{text} blocks), the informal parts may again refer
+  to formal entities by means of ``antiquotations'' (such as
   \texttt{\at}\verb,{text "'a bintree"}, or
   \texttt{\at}\verb,{typ 'a},), see also \S\ref{sec:doc-prep-text}.
 *}
 
 

 
 text {*
   In contrast to the highly interactive mode of Isabelle/Isar theory
   development, the document preparation stage essentially works in
   batch-mode.  An Isabelle \bfindex{session} consists of a collection
-  of source files that may contribute to an output document.
-  Each session is derived from a single parent, usually
-  an object-logic image like \texttt{HOL}.  This results in an overall
-  tree structure, which is reflected by the output location in the
-  file system (usually rooted at \verb,~/isabelle/browser_info,).
+  of source files that may contribute to an output document.  Each
+  session is derived from a single parent, usually an object-logic
+  image like \texttt{HOL}.  This results in an overall tree structure,
+  which is reflected by the output location in the file system
+  (usually rooted at \verb,~/isabelle/browser_info,).
 
   \medskip The easiest way to manage Isabelle sessions is via
   \texttt{isatool mkdir} (generates an initial session source setup)
   and \texttt{isatool make} (run sessions controlled by
   \texttt{IsaMakefile}).  For example, a new session

   The \texttt{isatool make} job also informs about the file-system
   location of the ultimate results.  The above dry run should be able
   to produce some \texttt{document.pdf} (with dummy title, empty table
   of contents etc.).  Any failure at this stage usually indicates
   technical problems of the {\LaTeX} installation.\footnote{Especially
-  make sure that \texttt{pdflatex} is present; if all fails one may
+  make sure that \texttt{pdflatex} is present; if in doubt one may
   fall back on DVI output by changing \texttt{usedir} options in
   \texttt{IsaMakefile} \cite{isabelle-sys}.}
 
   \medskip The detailed arrangement of the session sources is as
   follows.

   \texttt{isatool usedir} and \texttt{isatool make}.
 
   \end{itemize}
 
   One may now start to populate the directory \texttt{MySession}, and
-  the file \texttt{MySession/ROOT.ML} accordingly.
-  The file \texttt{MySession/document/root.tex} should also be adapted at some
+  the file \texttt{MySession/ROOT.ML} accordingly.  The file
+  \texttt{MySession/document/root.tex} should also be adapted at some
   point; the default version is mostly self-explanatory.  Note that
   \verb,\isabellestyle, enables fine-tuning of the general appearance
   of characters and mathematical symbols (see also
   \S\ref{sec:doc-prep-symbols}).
 

   distributed with Isabelle. Further packages may be required in
   particular applications, say for unusual mathematical symbols.
 
   \medskip Any additional files for the {\LaTeX} stage go into the
   \texttt{MySession/document} directory as well.  In particular,
-  adding a file named \texttt{root.bib} causes an
-  automatic run of \texttt{bibtex} to process a bibliographic
-  database; see also \texttt{isatool document} \cite{isabelle-sys}.
+  adding a file named \texttt{root.bib} causes an automatic run of
+  \texttt{bibtex} to process a bibliographic database; see also
+  \texttt{isatool document} \cite{isabelle-sys}.
 
   \medskip Any failure of the document preparation phase in an
   Isabelle batch session leaves the generated sources in their target
-  location, identified by the accompanying error message.  This
-  lets you trace {\LaTeX} problems with the generated files at
-  hand.
+  location, identified by the accompanying error message.  This lets
+  you trace {\LaTeX} problems with the generated files at hand.
 *}
 
 
 subsection {* Structure Markup *}
 

 
   From the Isabelle perspective, each markup command takes a single
   $text$ argument (delimited by \verb,",~@{text \<dots>}~\verb,", or
   \verb,{,\verb,*,~@{text \<dots>}~\verb,*,\verb,},).  After stripping any
   surrounding white space, the argument is passed to a {\LaTeX} macro
-  \verb,\isamarkupXYZ, for any command \isakeyword{XYZ}.  These macros
-  are defined in \verb,isabelle.sty, according to the meaning given in
-  the rightmost column above.
+  \verb,\isamarkupXYZ, for command \isakeyword{XYZ}.  These macros are
+  defined in \verb,isabelle.sty, according to the meaning given in the
+  rightmost column above.
 
   \medskip The following source fragment illustrates structure markup
   of a theory.  Note that {\LaTeX} labels may be included inside of
   section headings as well.
 

   subsection {\ttlbrace}* Main theorem {\ttback}label{\ttlbrace}sec:main-theorem{\ttrbrace} *{\ttrbrace}
 
   theorem main: \dots
 
   end
-  \end{ttbox}
-
-  You may occasionally want to change the meaning of markup
-  commands, say via \verb,\renewcommand, in \texttt{root.tex}.  For example,
-  \verb,\isamarkupheader, is a good candidate for some tuning.
-  We could
-  move it up in the hierarchy to become \verb,\chapter,.
+  \end{ttbox}\vspace{-\medskipamount}
+
+  You may occasionally want to change the meaning of markup commands,
+  say via \verb,\renewcommand, in \texttt{root.tex}.  For example,
+  \verb,\isamarkupheader, is a good candidate for some tuning.  We
+  could move it up in the hierarchy to become \verb,\chapter,.
 
 \begin{verbatim}
   \renewcommand{\isamarkupheader}[1]{\chapter{#1}}
 \end{verbatim}
 
-  \noindent Now we must change the
-  document class given in \texttt{root.tex} to something that supports
-  chapters.  A suitable command is
-  \verb,\documentclass{report},.
+  \noindent Now we must change the document class given in
+  \texttt{root.tex} to something that supports chapters.  A suitable
+  command is \verb,\documentclass{report},.
 
   \medskip The {\LaTeX} macro \verb,\isabellecontext, is maintained to
   hold the name of the current theory context.  This is particularly
   useful for document headings:
 

 
 \begin{verbatim}
   \renewcommand{\isastyletxt}{\isastyletext}
 \end{verbatim}
 
-  \medskip The $text$ part of these markup commands
-  essentially inserts \emph{quoted material} into a
-  formal text, mainly for instruction of the reader.  An
-  \bfindex{antiquotation} is again a formal object embedded into such
-  an informal portion.  The interpretation of antiquotations is
-  limited to some well-formedness checks, with the result being pretty
-  printed to the resulting document.  Quoted text blocks together with
-  antiquotations provide an attractive means of referring to formal
-  entities, with good confidence in getting the technical details
-  right (especially syntax and types).
+  \medskip The $text$ part of Isabelle markup commands essentially
+  inserts \emph{quoted material} into a formal text, mainly for
+  instruction of the reader.  An \bfindex{antiquotation} is again a
+  formal object embedded into such an informal portion.  The
+  interpretation of antiquotations is limited to some well-formedness
+  checks, with the result being pretty printed to the resulting
+  document.  Quoted text blocks together with antiquotations provide
+  an attractive means of referring to formal entities, with good
+  confidence in getting the technical details right (especially syntax
+  and types).
 
   The general syntax of antiquotations is as follows:
   \texttt{{\at}{\ttlbrace}$name$ $arguments${\ttrbrace}}, or
   \texttt{{\at}{\ttlbrace}$name$ [$options$] $arguments${\ttrbrace}}
   for a comma-separated list of options consisting of a $name$ or
-  \texttt{$name$=$value$}.  The syntax of $arguments$ depends on the
-  kind of antiquotation, it generally follows the same conventions for
-  types, terms, or theorems as in the formal part of a theory.
-
-  \medskip This sentence demonstrates quotations and antiquotations: 
-      @{term "%x y. x"} is a well-typed term.
+  \texttt{$name$=$value$} each.  The syntax of $arguments$ depends on
+  the kind of antiquotation, it generally follows the same conventions
+  for types, terms, or theorems as in the formal part of a theory.
+
+  \medskip This sentence demonstrates quotations and antiquotations:
+  @{term "%x y. x"} is a well-typed term.
 
   \medskip\noindent The output above was produced as follows:
   \begin{ttbox}
 text {\ttlbrace}*
   This sentence demonstrates quotations and antiquotations:
   {\at}{\ttlbrace}term "%x y. x"{\ttrbrace} is a well-typed term.
 *{\ttrbrace}
-  \end{ttbox}
+  \end{ttbox}\vspace{-\medskipamount}
 
   The notational change from the ASCII character~\verb,%, to the
-  symbol~@{text \<lambda>} reveals that Isabelle printed this term, 
-  after parsing and type-checking.  Document preparation
-  enables symbolic output by default.
+  symbol~@{text \<lambda>} reveals that Isabelle printed this term, after
+  parsing and type-checking.  Document preparation enables symbolic
+  output by default.
 
   \medskip The next example includes an option to modify Isabelle's
   \verb,show_types, flag.  The antiquotation
-  \texttt{{\at}}\verb,{term [show_types] "%x y. x"}, produces 
-  the output @{term [show_types] "%x y. x"}.
-  Type inference has figured out the most
-  general typings in the present theory context.  Terms
-  may acquire different typings due to constraints imposed
-  by their environment; within a proof, for example, variables are given
-  the same types as they have in the main goal statement.
+  \texttt{{\at}}\verb,{term [show_types] "%x y. x"}, produces the
+  output @{term [show_types] "%x y. x"}.  Type inference has figured
+  out the most general typings in the present theory context.  Terms
+  may acquire different typings due to constraints imposed by their
+  environment; within a proof, for example, variables are given the
+  same types as they have in the main goal statement.
 
   \medskip Several further kinds of antiquotations and options are
   available \cite{isabelle-sys}.  Here are a few commonly used
   combinations:
 

 
   For example, \texttt{\at}\verb,{text "\<forall>\<exists>"}, produces @{text
   "\<forall>\<exists>"}, according to the standard interpretation of these symbol
   (cf.\ \S\ref{sec:doc-prep-symbols}).  Thus we achieve consistent
   mathematical notation in both the formal and informal parts of the
-  document very easily.  Manual {\LaTeX} code would leave more control
-  over the typesetting, but is also slightly more tedious.
+  document very easily, independently of the term language of
+  Isabelle.  Manual {\LaTeX} code would leave more control over the
+  typesetting, but is also slightly more tedious.
 *}
 
 
 subsection {* Interpretation of Symbols \label{sec:doc-prep-symbols} *}
 

   straightforward generalization of ASCII characters.  While Isabelle
   does not impose any interpretation of the infinite collection of
   named symbols, {\LaTeX} documents use canonical glyphs for certain
   standard symbols \cite[appendix~A]{isabelle-sys}.
 
-  The {\LaTeX} code produced from Isabelle text follows a 
-  simple scheme.  You can tune the final appearance by
-  redefining certain macros, say in \texttt{root.tex} of the document.
+  The {\LaTeX} code produced from Isabelle text follows a simple
+  scheme.  You can tune the final appearance by redefining certain
+  macros, say in \texttt{root.tex} of the document.
 
   \begin{enumerate}
 
   \item 7-bit ASCII characters: letters \texttt{A\dots Z} and
   \texttt{a\dots z} are output directly, digits are passed as an
   argument to the \verb,\isadigit, macro, other characters are
   replaced by specifically named macros of the form
   \verb,\isacharXYZ,.
 
-  \item Named symbols: \verb,\,\verb,<,$XYZ$\verb,>, is turned into
-  \verb,{\isasym,$XYZ$\verb,},; note the additional braces.
-
-  \item Named control symbols: \verb,\,\verb,<^,$XYZ$\verb,>, is
-  turned into \verb,\isactrl,$XYZ$; subsequent symbols may act as
-  arguments if the corresponding macro is defined accordingly.
+  \item Named symbols: \verb,\,\verb,<XYZ>, is turned into
+  \verb,{\isasymXYZ},; note the additional braces.
+
+  \item Named control symbols: \verb,\,\verb,<^XYZ>, is turned into
+  \verb,\isactrlXYZ,; subsequent symbols may act as arguments if the
+  control macro is defined accordingly.
 
   \end{enumerate}
 
   You may occasionally wish to give new {\LaTeX} interpretations of
   named symbols.  This merely requires an appropriate definition of
-  \verb,\isasym,$XYZ$\verb,, for \verb,\,\verb,<,$XYZ$\verb,>, (see
+  \verb,\isasymXYZ,, for \verb,\,\verb,<XYZ>, (see
   \texttt{isabelle.sty} for working examples).  Control symbols are
   slightly more difficult to get right, though.
 
   \medskip The \verb,\isabellestyle, macro provides a high-level
   interface to tune the general appearance of individual symbols.  For

   Alternatively, one may tune the theory loading process in
   \texttt{ROOT.ML} itself: traversal of the theory dependency graph
   may be fine-tuned by adding \verb,use_thy, invocations, although
   topological sorting still has to be observed.  Moreover, the ML
   operator \verb,no_document, temporarily disables document generation
-  while executing a theory loader command; its usage is like this:
+  while executing a theory loader command.  Its usage is like this:
 
 \begin{verbatim}
   no_document use_thy "T";
 \end{verbatim}
 
-  \medskip Theory output may be suppressed more selectively.
-  Research articles and slides usually do not include the
-  formal content in full.  In order to delimit \bfindex{ignored
-  material}, special source comments
-  \verb,(,\verb,*,\verb,<,\verb,*,\verb,), and
-  \verb,(,\verb,*,\verb,>,\verb,*,\verb,), may be included in the
-  text.  Only document preparation is affected; the formal
-  checking of the theory is unchanged.
-
-  In this example, we suppress  a theory's uninteresting
-  \isakeyword{theory} and \isakeyword{end} brackets:
+  \medskip Theory output may be suppressed more selectively.  Research
+  articles and slides usually do not include the formal content in
+  full.  Delimiting \bfindex{ignored material} by the special source
+  comments \verb,(,\verb,*,\verb,<,\verb,*,\verb,), and
+  \verb,(,\verb,*,\verb,>,\verb,*,\verb,), tells the document
+  preparation system to suppress these parts; the formal checking of
+  the theory is unchanged.
+
+  In this example, we hide a theory's \isakeyword{theory} and
+  \isakeyword{end} brackets:
 
   \medskip
 
   \begin{tabular}{l}
   \verb,(,\verb,*,\verb,<,\verb,*,\verb,), \\

 
   \medskip
 
   Text may be suppressed in a fine-grained manner.  We may even hide
   vital parts of a proof, pretending that things have been simpler
-  than they really were.  For example, this ``fully automatic'' proof is
-  actually a fake:
+  than they really were.  For example, this ``fully automatic'' proof
+  is actually a fake:
 *}
 
 lemma "x \<noteq> (0::int) \<Longrightarrow> 0 < x * x"
   by (auto(*<*)simp add: int_less_le(*>*))
 

 \begin{verbatim}
   by (auto(*<*)simp add: int_less_le(*>*))
 \end{verbatim}
 %(*
 
-  \medskip Suppressing portions of printed text demands care.  
-  You should not misrepresent
-  the underlying theory development.  It is 
-  easy to invalidate the visible text by hiding 
-  references to questionable axioms.
+  \medskip Suppressing portions of printed text demands care.  You
+  should not misrepresent the underlying theory development.  It is
+  easy to invalidate the visible text by hiding references to
+  questionable axioms.
 
   Authentic reports of Isabelle/Isar theories, say as part of a
-  library, should suppress nothing.
-  Other users may need the full information for their own derivative
-  work.  If a particular formalization appears inadequate for general
-  public coverage, it is often more appropriate to think of a better
-  way in the first place.
+  library, should suppress nothing.  Other users may need the full
+  information for their own derivative work.  If a particular
+  formalization appears inadequate for general public coverage, it is
+  often more appropriate to think of a better way in the first place.
 
   \medskip Some technical subtleties of the
   \verb,(,\verb,*,\verb,<,\verb,*,\verb,),~\verb,(,\verb,*,\verb,>,\verb,*,\verb,),
   elements need to be kept in mind, too --- the system performs few
   sanity checks here.  Arguments of markup commands and formal