theory Document_Preparation

 imports Base Main

 begin

 chapter {* Document preparation \label{ch:document-prep} *}

 text {* Isabelle/Isar provides a simple document preparation system

   based on regular {PDF-\LaTeX} technology, with full support for

   hyper-links and bookmarks.  Thus the results are well suited for WWW

   browsing and as printed copies.

   \medskip Isabelle generates {\LaTeX} output while running a

   \emph{logic session} (see also \cite{isabelle-sys}).  Getting

   started with a working configuration for common situations is quite

   easy by using the Isabelle @{verbatim mkdir} and @{verbatim make}

   tools.  First invoke

 \begin{ttbox}

   isabelle mkdir Foo

 \end{ttbox}

   to initialize a separate directory for session @{verbatim Foo} (it

   is safe to experiment, since @{verbatim "isabelle mkdir"} never

   overwrites existing files).  Ensure that @{verbatim "Foo/ROOT.ML"}

   holds ML commands to load all theories required for this session;

   furthermore @{verbatim "Foo/document/root.tex"} should include any

   special {\LaTeX} macro packages required for your document (the

   default is usually sufficient as a start).

   The session is controlled by a separate @{verbatim IsaMakefile}

   (with crude source dependencies by default).  This file is located

   one level up from the @{verbatim Foo} directory location.  Now

   invoke

 \begin{ttbox}

   isabelle make Foo

 \end{ttbox}

   to run the @{verbatim Foo} session, with browser information and

   document preparation enabled.  Unless any errors are reported by

   Isabelle or {\LaTeX}, the output will appear inside the directory

   defined by the @{verbatim ISABELLE_BROWSER_INFO} setting (as

   reported by the batch job in verbose mode).

   \medskip You may also consider to tune the @{verbatim usedir}

   options in @{verbatim IsaMakefile}, for example to switch the output

   format between @{verbatim pdf} and @{verbatim dvi}, or activate the

   @{verbatim "-D"} option to retain a second copy of the generated

   {\LaTeX} sources (for manual inspection or separate runs of

   @{executable latex}).

   \medskip See \emph{The Isabelle System Manual} \cite{isabelle-sys}

   for further details on Isabelle logic sessions and theory

   presentation.  The Isabelle/HOL tutorial \cite{isabelle-hol-book}

   also covers theory presentation to some extent.

 *}

 section {* Markup commands \label{sec:markup} *}

 text {*

   \begin{matharray}{rcl}

     @{command_def "header"} & : & @{text "toplevel \<rightarrow> toplevel"} \\[0.5ex]

     @{command_def "chapter"} & : & @{text "local_theory \<rightarrow> local_theory"} \\

     @{command_def "section"} & : & @{text "local_theory \<rightarrow> local_theory"} \\

     @{command_def "subsection"} & : & @{text "local_theory \<rightarrow> local_theory"} \\

     @{command_def "subsubsection"} & : & @{text "local_theory \<rightarrow> local_theory"} \\

     @{command_def "text"} & : & @{text "local_theory \<rightarrow> local_theory"} \\

     @{command_def "text_raw"} & : & @{text "local_theory \<rightarrow> local_theory"} \\[0.5ex]

     @{command_def "sect"} & : & @{text "proof \<rightarrow> proof"} \\

     @{command_def "subsect"} & : & @{text "proof \<rightarrow> proof"} \\

     @{command_def "subsubsect"} & : & @{text "proof \<rightarrow> proof"} \\

     @{command_def "txt"} & : & @{text "proof \<rightarrow> proof"} \\

     @{command_def "txt_raw"} & : & @{text "proof \<rightarrow> proof"} \\

   \end{matharray}

   Markup commands provide a structured way to insert text into the

   document generated from a theory.  Each markup command takes a

   single @{syntax text} argument, which is passed as argument to a

   corresponding {\LaTeX} macro.  The default macros provided by

   @{file "~~/lib/texinputs/isabelle.sty"} can be redefined according

   to the needs of the underlying document and {\LaTeX} styles.

   Note that formal comments (\secref{sec:comments}) are similar to

   markup commands, but have a different status within Isabelle/Isar

   syntax.

   @{rail "

     (@@{command chapter} | @@{command section} | @@{command subsection} |

       @@{command subsubsection} | @@{command text}) @{syntax target}? @{syntax text}

     ;

     (@@{command header} | @@{command text_raw} | @@{command sect} | @@{command subsect} |

       @@{command subsubsect} | @@{command txt} | @@{command txt_raw}) @{syntax text}

   "}

   \begin{description}

   \item @{command header} provides plain text markup just preceding

   the formal beginning of a theory.  The corresponding {\LaTeX} macro

   is @{verbatim "\\isamarkupheader"}, which acts like @{command

   section} by default.

   \item @{command chapter}, @{command section}, @{command subsection},

   and @{command subsubsection} mark chapter and section headings

   within the main theory body or local theory targets.  The

   corresponding {\LaTeX} macros are @{verbatim "\\isamarkupchapter"},

   @{verbatim "\\isamarkupsection"}, @{verbatim

   "\\isamarkupsubsection"} etc.

   \item @{command sect}, @{command subsect}, and @{command subsubsect}

   mark section headings within proofs.  The corresponding {\LaTeX}

   macros are @{verbatim "\\isamarkupsect"}, @{verbatim

   "\\isamarkupsubsect"} etc.

   \item @{command text} and @{command txt} specify paragraphs of plain

   text.  This corresponds to a {\LaTeX} environment @{verbatim

   "\\begin{isamarkuptext}"} @{text "\<dots>"} @{verbatim

   "\\end{isamarkuptext}"} etc.

   \item @{command text_raw} and @{command txt_raw} insert {\LaTeX}

   source into the output, without additional markup.  Thus the full

   range of document manipulations becomes available, at the risk of

   messing up document output.

   \end{description}

   Except for @{command "text_raw"} and @{command "txt_raw"}, the text

   passed to any of the above markup commands may refer to formal

   entities via \emph{document antiquotations}, see also

   \secref{sec:antiq}.  These are interpreted in the present theory or

   proof context, or the named @{text "target"}.

   \medskip The proof markup commands closely resemble those for theory

   specifications, but have a different formal status and produce

   different {\LaTeX} macros.  The default definitions coincide for

   analogous commands such as @{command section} and @{command sect}.

 *}

 section {* Document Antiquotations \label{sec:antiq} *}

 text {*

   \begin{matharray}{rcl}

     @{antiquotation_def "theory"} & : & @{text antiquotation} \\

     @{antiquotation_def "thm"} & : & @{text antiquotation} \\

     @{antiquotation_def "lemma"} & : & @{text antiquotation} \\

     @{antiquotation_def "prop"} & : & @{text antiquotation} \\

     @{antiquotation_def "term"} & : & @{text antiquotation} \\

     @{antiquotation_def term_type} & : & @{text antiquotation} \\

     @{antiquotation_def typeof} & : & @{text antiquotation} \\

     @{antiquotation_def const} & : & @{text antiquotation} \\

     @{antiquotation_def abbrev} & : & @{text antiquotation} \\

     @{antiquotation_def typ} & : & @{text antiquotation} \\

     @{antiquotation_def type} & : & @{text antiquotation} \\

     @{antiquotation_def class} & : & @{text antiquotation} \\

     @{antiquotation_def "text"} & : & @{text antiquotation} \\

     @{antiquotation_def goals} & : & @{text antiquotation} \\

     @{antiquotation_def subgoals} & : & @{text antiquotation} \\

     @{antiquotation_def prf} & : & @{text antiquotation} \\

     @{antiquotation_def full_prf} & : & @{text antiquotation} \\

     @{antiquotation_def ML} & : & @{text antiquotation} \\

     @{antiquotation_def ML_type} & : & @{text antiquotation} \\

     @{antiquotation_def ML_struct} & : & @{text antiquotation} \\

     @{antiquotation_def "file"} & : & @{text antiquotation} \\

   \end{matharray}

   The overall content of an Isabelle/Isar theory may alternate between

   formal and informal text.  The main body consists of formal

   specification and proof commands, interspersed with markup commands

   (\secref{sec:markup}) or document comments (\secref{sec:comments}).

   The argument of markup commands quotes informal text to be printed

   in the resulting document, but may again refer to formal entities

   via \emph{document antiquotations}.

   For example, embedding of ``@{text [source=false] "@{term [show_types] \"f x = a + x\"}"}''

   within a text block makes

   \isa{{\isacharparenleft}f{\isasymColon}{\isacharprime}a\ {\isasymRightarrow}\ {\isacharprime}a{\isacharparenright}\ {\isacharparenleft}x{\isasymColon}{\isacharprime}a{\isacharparenright}\ {\isacharequal}\ {\isacharparenleft}a{\isasymColon}{\isacharprime}a{\isacharparenright}\ {\isacharplus}\ x} appear in the final {\LaTeX} document.

   Antiquotations usually spare the author tedious typing of logical

   entities in full detail.  Even more importantly, some degree of

   consistency-checking between the main body of formal text and its

   informal explanation is achieved, since terms and types appearing in

   antiquotations are checked within the current theory or proof

   context.

   %% FIXME less monolithic presentation, move to individual sections!?

   @{rail "

     '@{' antiquotation '}'

     ;

     @{syntax_def antiquotation}:

       @@{antiquotation theory} options @{syntax name} |

       @@{antiquotation thm} options styles @{syntax thmrefs} |

       @@{antiquotation lemma} options @{syntax prop} @'by' @{syntax method} @{syntax method}? |

       @@{antiquotation prop} options styles @{syntax prop} |

       @@{antiquotation term} options styles @{syntax term} |

       @@{antiquotation (HOL) value} options styles @{syntax term} |

       @@{antiquotation term_type} options styles @{syntax term} |

       @@{antiquotation typeof} options styles @{syntax term} |

       @@{antiquotation const} options @{syntax term} |

       @@{antiquotation abbrev} options @{syntax term} |

       @@{antiquotation typ} options @{syntax type} |

       @@{antiquotation type} options @{syntax name} |

       @@{antiquotation class} options @{syntax name} |

       @@{antiquotation text} options @{syntax name} |

       @@{antiquotation goals} options |

       @@{antiquotation subgoals} options |

       @@{antiquotation prf} options @{syntax thmrefs} |

       @@{antiquotation full_prf} options @{syntax thmrefs} |

       @@{antiquotation ML} options @{syntax name} |

       @@{antiquotation ML_type} options @{syntax name} |

       @@{antiquotation ML_struct} options @{syntax name} |

       @@{antiquotation \"file\"} options @{syntax name}

     ;

     options: '[' (option * ',') ']'

     ;

     option: @{syntax name} | @{syntax name} '=' @{syntax name}

     ;

     styles: '(' (style + ',') ')'

     ;

     style: (@{syntax name} +)

   "}

   Note that the syntax of antiquotations may \emph{not} include source

   comments @{verbatim "(*"}~@{text "\<dots>"}~@{verbatim "*)"} nor verbatim

   text @{verbatim "{"}@{verbatim "*"}~@{text "\<dots>"}~@{verbatim

   "*"}@{verbatim "}"}.

   \begin{description}

   \item @{text "@{theory A}"} prints the name @{text "A"}, which is

   guaranteed to refer to a valid ancestor theory in the current

   context.

   \item @{text "@{thm a\<^sub>1 \<dots> a\<^sub>n}"} prints theorems @{text "a\<^sub>1 \<dots> a\<^sub>n"}.

   Full fact expressions are allowed here, including attributes

   (\secref{sec:syn-att}).

   \item @{text "@{prop \<phi>}"} prints a well-typed proposition @{text

   "\<phi>"}.

   \item @{text "@{lemma \<phi> by m}"} proves a well-typed proposition

   @{text "\<phi>"} by method @{text m} and prints the original @{text "\<phi>"}.

   \item @{text "@{term t}"} prints a well-typed term @{text "t"}.

   \item @{text "@{value t}"} evaluates a term @{text "t"} and prints

   its result, see also @{command_ref (HOL) value}.

   \item @{text "@{term_type t}"} prints a well-typed term @{text "t"}

   annotated with its type.

   \item @{text "@{typeof t}"} prints the type of a well-typed term

   @{text "t"}.

   \item @{text "@{const c}"} prints a logical or syntactic constant

   @{text "c"}.

   \item @{text "@{abbrev c x\<^sub>1 \<dots> x\<^sub>n}"} prints a constant abbreviation

   @{text "c x\<^sub>1 \<dots> x\<^sub>n \<equiv> rhs"} as defined in the current context.

   \item @{text "@{typ \<tau>}"} prints a well-formed type @{text "\<tau>"}.

   \item @{text "@{type \<kappa>}"} prints a (logical or syntactic) type

     constructor @{text "\<kappa>"}.

   \item @{text "@{class c}"} prints a class @{text c}.

   \item @{text "@{text s}"} prints uninterpreted source text @{text

   s}.  This is particularly useful to print portions of text according

   to the Isabelle document style, without demanding well-formedness,

   e.g.\ small pieces of terms that should not be parsed or

   type-checked yet.

   \item @{text "@{goals}"} prints the current \emph{dynamic} goal

   state.  This is mainly for support of tactic-emulation scripts

   within Isar.  Presentation of goal states does not conform to the

   idea of human-readable proof documents!

   When explaining proofs in detail it is usually better to spell out

   the reasoning via proper Isar proof commands, instead of peeking at

   the internal machine configuration.

   \item @{text "@{subgoals}"} is similar to @{text "@{goals}"}, but

   does not print the main goal.

   \item @{text "@{prf a\<^sub>1 \<dots> a\<^sub>n}"} prints the (compact) proof terms

   corresponding to the theorems @{text "a\<^sub>1 \<dots> a\<^sub>n"}. Note that this

   requires proof terms to be switched on for the current logic

   session.

   \item @{text "@{full_prf a\<^sub>1 \<dots> a\<^sub>n}"} is like @{text "@{prf a\<^sub>1 \<dots>

   a\<^sub>n}"}, but prints the full proof terms, i.e.\ also displays

   information omitted in the compact proof term, which is denoted by

   ``@{text _}'' placeholders there.

   \item @{text "@{ML s}"}, @{text "@{ML_type s}"}, and @{text

   "@{ML_struct s}"} check text @{text s} as ML value, type, and

   structure, respectively.  The source is printed verbatim.

   \item @{text "@{file path}"} checks that @{text "path"} refers to a

   file (or directory) and prints it verbatim.

   \end{description}

 *}

 subsection {* Styled antiquotations *}

 text {* The antiquotations @{text thm}, @{text prop} and @{text

   term} admit an extra \emph{style} specification to modify the

   printed result.  A style is specified by a name with a possibly

   empty number of arguments;  multiple styles can be sequenced with

   commas.  The following standard styles are available:

   \begin{description}

   \item @{text lhs} extracts the first argument of any application

   form with at least two arguments --- typically meta-level or

   object-level equality, or any other binary relation.

   \item @{text rhs} is like @{text lhs}, but extracts the second

   argument.

   \item @{text "concl"} extracts the conclusion @{text C} from a rule

   in Horn-clause normal form @{text "A\<^sub>1 \<Longrightarrow> \<dots> A\<^sub>n \<Longrightarrow> C"}.

   \item @{text "prem"} @{text n} extract premise number

   @{text "n"} from from a rule in Horn-clause

   normal form @{text "A\<^sub>1 \<Longrightarrow> \<dots> A\<^sub>n \<Longrightarrow> C"}

   \end{description}

 *}

 subsection {* General options *}

 text {* The following options are available to tune the printed output

   of antiquotations.  Note that many of these coincide with global ML

   flags of the same names.

   \begin{description}

   \item @{antiquotation_option_def show_types}~@{text "= bool"} and

   @{antiquotation_option_def show_sorts}~@{text "= bool"} control

   printing of explicit type and sort constraints.

   \item @{antiquotation_option_def show_structs}~@{text "= bool"}

   controls printing of implicit structures.

   \item @{antiquotation_option_def show_abbrevs}~@{text "= bool"}

   controls folding of abbreviations.

   \item @{antiquotation_option_def names_long}~@{text "= bool"} forces

   names of types and constants etc.\ to be printed in their fully

   qualified internal form.

   \item @{antiquotation_option_def names_short}~@{text "= bool"}

   forces names of types and constants etc.\ to be printed unqualified.

   Note that internalizing the output again in the current context may

   well yield a different result.

   \item @{antiquotation_option_def names_unique}~@{text "= bool"}

   determines whether the printed version of qualified names should be

   made sufficiently long to avoid overlap with names declared further

   back.  Set to @{text false} for more concise output.

   \item @{antiquotation_option_def eta_contract}~@{text "= bool"}

   prints terms in @{text \<eta>}-contracted form.

   \item @{antiquotation_option_def display}~@{text "= bool"} indicates

   if the text is to be output as multi-line ``display material'',

   rather than a small piece of text without line breaks (which is the

   default).

   In this mode the embedded entities are printed in the same style as

   the main theory text.

   \item @{antiquotation_option_def break}~@{text "= bool"} controls

   line breaks in non-display material.

   \item @{antiquotation_option_def quotes}~@{text "= bool"} indicates

   if the output should be enclosed in double quotes.

   \item @{antiquotation_option_def mode}~@{text "= name"} adds @{text

   name} to the print mode to be used for presentation.  Note that the

   standard setup for {\LaTeX} output is already present by default,

   including the modes @{text latex} and @{text xsymbols}.

   \item @{antiquotation_option_def margin}~@{text "= nat"} and

   @{antiquotation_option_def indent}~@{text "= nat"} change the margin

   or indentation for pretty printing of display material.

   \item @{antiquotation_option_def goals_limit}~@{text "= nat"}

   determines the maximum number of goals to be printed (for goal-based

   antiquotation).

   \item @{antiquotation_option_def source}~@{text "= bool"} prints the

   original source text of the antiquotation arguments, rather than its

   internal representation.  Note that formal checking of

   @{antiquotation "thm"}, @{antiquotation "term"}, etc. is still

   enabled; use the @{antiquotation "text"} antiquotation for unchecked

   output.

   Regular @{text "term"} and @{text "typ"} antiquotations with @{text

   "source = false"} involve a full round-trip from the original source

   to an internalized logical entity back to a source form, according

   to the syntax of the current context.  Thus the printed output is

   not under direct control of the author, it may even fluctuate a bit

   as the underlying theory is changed later on.

   In contrast, @{antiquotation_option source}~@{text "= true"}

   admits direct printing of the given source text, with the desirable

   well-formedness check in the background, but without modification of

   the printed text.

   \end{description}

   For boolean flags, ``@{text "name = true"}'' may be abbreviated as

   ``@{text name}''.  All of the above flags are disabled by default,

   unless changed from ML, say in the @{verbatim "ROOT.ML"} of the

   logic session.

 *}

 section {* Markup via command tags \label{sec:tags} *}

 text {* Each Isabelle/Isar command may be decorated by additional

   presentation tags, to indicate some modification in the way it is

   printed in the document.

   @{rail "

     @{syntax_def tags}: ( tag * )

     ;

     tag: '%' (@{syntax ident} | @{syntax string})

   "}

   Some tags are pre-declared for certain classes of commands, serving

   as default markup if no tags are given in the text:

   \medskip

   \begin{tabular}{ll}

     @{text "theory"} & theory begin/end \\

     @{text "proof"} & all proof commands \\

     @{text "ML"} & all commands involving ML code \\

   \end{tabular}

   \medskip The Isabelle document preparation system

   \cite{isabelle-sys} allows tagged command regions to be presented

   specifically, e.g.\ to fold proof texts, or drop parts of the text

   completely.

   For example ``@{command "by"}~@{text "%invisible auto"}'' causes

   that piece of proof to be treated as @{text invisible} instead of

   @{text "proof"} (the default), which may be shown or hidden

   depending on the document setup.  In contrast, ``@{command

   "by"}~@{text "%visible auto"}'' forces this text to be shown

   invariably.

   Explicit tag specifications within a proof apply to all subsequent

   commands of the same level of nesting.  For example, ``@{command

   "proof"}~@{text "%visible \<dots>"}~@{command "qed"}'' forces the whole

   sub-proof to be typeset as @{text visible} (unless some of its parts

   are tagged differently).

   \medskip Command tags merely produce certain markup environments for

   type-setting.  The meaning of these is determined by {\LaTeX}

   macros, as defined in @{file "~~/lib/texinputs/isabelle.sty"} or

   by the document author.  The Isabelle document preparation tools

   also provide some high-level options to specify the meaning of

   arbitrary tags to ``keep'', ``drop'', or ``fold'' the corresponding

   parts of the text.  Logic sessions may also specify ``document

   versions'', where given tags are interpreted in some particular way.

   Again see \cite{isabelle-sys} for further details.

 *}

 section {* Railroad diagrams *}

 text {*

   \begin{matharray}{rcl}

     @{antiquotation_def "rail"} & : & @{text antiquotation} \\

   \end{matharray}

   @{rail "'rail' string"}

   The @{antiquotation rail} antiquotation allows to include syntax

   diagrams into Isabelle documents.  {\LaTeX} requires the style file

   @{"file" "~~/lib/texinputs/pdfsetup.sty"}, which can be used via

   @{verbatim "\\usepackage{pdfsetup}"} in @{verbatim "root.tex"}, for

   example.

   The rail specification language is quoted here as Isabelle @{syntax

   string}; it has its own grammar given below.

   @{rail "

   rule? + ';'

   ;

   rule: ((identifier | @{syntax antiquotation}) ':')? body

   ;

   body: concatenation + '|'

   ;

   concatenation: ((atom '?'?) +) (('*' | '+') atom?)?

   ;

   atom: '(' body? ')' | identifier |

     '@'? (string | @{syntax antiquotation}) |

     '\\\\\\\\'

   "}

   The lexical syntax of @{text "identifier"} coincides with that of

   @{syntax ident} in regular Isabelle syntax, but @{text string} uses

   single quotes instead of double quotes of the standard @{syntax

   string} category, to avoid extra escapes.

   Each @{text rule} defines a formal language (with optional name),

   using a notation that is similar to EBNF or regular expressions with

   recursion.  The meaning and visual appearance of these rail language

   elements is illustrated by the following representative examples.

   \begin{itemize}

   \item Empty @{verbatim "()"}

   @{rail "()"}

   \item Nonterminal @{verbatim "A"}

   @{rail "A"}

   \item Nonterminal via Isabelle antiquotation

   @{verbatim "@{syntax method}"}

   @{rail "@{syntax method}"}

   \item Terminal @{verbatim "'xyz'"}

   @{rail "'xyz'"}

   \item Terminal in keyword style @{verbatim "@'xyz'"}

   @{rail "@'xyz'"}

   \item Terminal via Isabelle antiquotation

   @{verbatim "@@{method rule}"}

   @{rail "@@{method rule}"}

   \item Concatenation @{verbatim "A B C"}

   @{rail "A B C"}

   \item Linebreak @{verbatim "\\\\"} inside

   concatenation\footnote{Strictly speaking, this is only a single

   backslash, but the enclosing @{syntax string} syntax requires a

   second one for escaping.} @{verbatim "A B C \\\\ D E F"}

   @{rail "A B C \\ D E F"}

   \item Variants @{verbatim "A | B | C"}

   @{rail "A | B | C"}

   \item Option @{verbatim "A ?"}

   @{rail "A ?"}

   \item Repetition @{verbatim "A *"}

   @{rail "A *"}

   \item Repetition with separator @{verbatim "A * sep"}

   @{rail "A * sep"}

   \item Strict repetition @{verbatim "A +"}

   @{rail "A +"}

   \item Strict repetition with separator @{verbatim "A + sep"}

   @{rail "A + sep"}

   \end{itemize}

 *}

 section {* Draft presentation *}

 text {*

   \begin{matharray}{rcl}

     @{command_def "display_drafts"}@{text "\<^sup>*"} & : & @{text "any \<rightarrow>"} \\

     @{command_def "print_drafts"}@{text "\<^sup>*"} & : & @{text "any \<rightarrow>"} \\

   \end{matharray}

   @{rail "

     (@@{command display_drafts} | @@{command print_drafts}) (@{syntax name} +)

   "}

   \begin{description}

   \item @{command "display_drafts"}~@{text paths} and @{command

   "print_drafts"}~@{text paths} perform simple output of a given list

   of raw source files.  Only those symbols that do not require

   additional {\LaTeX} packages are displayed properly, everything else

   is left verbatim.

   \end{description}

 *}

 end