path: root/doc/NewDoc.texi

\input texinfo   @c -*-texinfo-*-
@c
@c $Id$
@c
@c %**start of header
@setfilename ProofGeneral.info
@settitle Proof General
@setchapternewpage odd
@paragraphindent 0
@iftex
@afourpaper
@end iftex
@c %**end of header

@c 
@c TODO, priority order
@c   . finish incomplete sections
@c   . polish mark-up
@c   . add more index entries
@c   . screenshots might be nice (one day)
@c   

@c NOTE ON THIS TEXINFO FILE:
@c I've tried keep full node lines *out* of this file because Emacs makes a
@c mess of updating them.  Instead, rely on makeinfo and friends to do
@c the equivalent job.  For this to work, we must follow each node
@c immediately with a section command, i.e.:
@c
@c  @node node-name
@c  <section-command>
@c
@c And each section with lower levels must have a menu command in
@c it.  Menu updating with Emacs is a bit better than node updating,
@c but tends to delete the first section of the file in XEmacs!
@c (it's better in FSF Emacs at the time of writing).
@c


@set version 2.0
@set xemacsversion 20.4
@set fsfversion 20.2
@set last-update November 1998
@set rcsid $Id$

@ifinfo
@format
START-INFO-DIR-ENTRY * ProofGeneral::Organize your proofs with Emacs!
END-INFO-DIR-ENTRY
@end format
@end ifinfo

@c
@c MACROS
@c
@c define one here for a command with a keybinding?
@c
@c I like the idea, but it's maybe against the texinfo
@c style to fix together a command and its keybinding.


@c merge functions and variables into concept index.
@c @syncodeindex fn cp
@c @syncodeindex vr cp

@c merge functions into variables index
@c @syncodeindex fn vr

@finalout
@titlepage
@title Proof General
@subtitle Organise your proofs with Emacs!
@subtitle Proof General @value{version}
@subtitle @value{last-update}
@iftex
@image{ProofGeneral}
@end iftex
@author D. Aspinall, H. Goguen, T. Kleymann and D. Sequeira
@page
@vskip 0pt plus 1filll
This manual and the program Proof General are
Copyright @copyright{} 1998 Proof General team, LFCS Edinburgh.


@c
@c COPYING NOTICE
@c
@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission notice
identical to this one except for the removal of this paragraph (this
paragraph not being relevant to the printed manual).
@end ignore

@sp 2
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.  
@sp 2

This manual documents Proof General, Version @value{version}, for use
with XEmacs @value{xemacsversion} and FSF GNU Emacs @value{fsfversion}
or later versions.

Version control stamp: @code{@value{rcsid}}
@end titlepage

@page


@ifinfo
@node Top
@top Proof General

This file documents version @value{version} of @b{Proof General}, a
generic Emacs interface for proof assistants.

Proof General @value{version} has been tested with XEmacs
@value{xemacsversion} and FSF GNU Emacs @value{fsfversion}.  It is
supplied ready customized for the proof assistants Coq, Lego, and
Isabelle.

@menu
* Introducing Proof General::   
* Basic Script Management::     
* Advanced Script Management::  
* Support for other Packages::  
* Customizing Proof General::   
* LEGO Proof General::          
* Coq Proof General::           
* Isabelle Proof General::      
* Adapting Proof General to New Provers::  
* Internals of Proof General::  
* Credits and References::      
* Obtaining and Installing Proof General::  
* Known bugs and workarounds::  
* Plans and ideas::             
* Function Index::                       
* Variable Index::                       
* Keystroke Index::             
* Index::                       
@end menu

@detailmenu  --- The Detailed Node Listing ---

Introducing Proof General

* Quick start guide::           
* Features of Proof General::   
* Supported proof assistants::  
* Prerequisites for this manual::

Basic Script Management

* Proof scripts::               
* Script buffers::              
* Summary of Proof General buffers::               
* Script editing commands::     
* Script processing commands::  
* Toolbar commands::            
* Proof assistant commands::    
* Walkthrough example in LEGO::  

Script buffers

* Locked queue and editing regions::  
* Goal-save sequences::         
* Active scripting buffer::     

Advanced Script Management

* Switching between proof scripts::  
* View of processed files ::    
* Retracting across files::     
* Asserting across files::      
* Working directly with the proof shell::  

Support for other Packages

* Support for function menus::  
* Support for outline mode::    
* Support for tags::            

Customizing Proof General

* Easy customization::          
* Display customization::       
* User options::                
* Changing faces::              
* Tweaking configuration settings::  

LEGO Proof General

* LEGO specific commands::      
* LEGO tags::                   
* LEGO customizations::         

Coq Proof General

* Coq specific commands::       
* Coq customizations::          

Isabelle Proof General

* Theory files::                
* Isabelle specific commands::  
* Isabelle customizations::     

Adapting Proof General to New Provers

* Overview of adding a new prover::            
* Major modes used by Proof General::  
* Menus and user-level commands::  
* Proof script settings::       
* Proof shell settings::        
* Goals buffer configuration::  
* Global constants::            
* Handling multiple files::     

Internals of Proof General

* Spans::                       
* Global variables::            
* Proof script mode::           
* Proof shell mode::            

Credits and References

* Credits::                     
* References::                  

Obtaining and Installing Proof General

* Obtaining Proof General::     
* Installing Proof General from tarball::  
* Installing Proof General from RPM package::  
* Notes for syssies::           

Known bugs and workarounds

* Bugs at the generic level::   
* Bugs specific to LEGO Proof General::  
* Bugs specific to Coq Proof General::  
* Bugs specific to Isabelle Proof General::  

Bugs specific to LEGO Proof General

* Retraction and Discharge::    
* Retraction and proving::      

Plans and ideas

* Granularity of atomic command sequences::  
* Browser mode for script files and theories::  
@end detailmenu
@end ifinfo



@c
@c CHAPTER: Introduction
@c
@node Introducing Proof General
@chapter Introducing Proof General
@cindex proof assistant
@cindex Proof General

@c would like the logo on the title page really but
@c it doesn't seem to work there for html.
@ifhtml
<IMG SRC="ProofGeneral.jpg" ALT="[ Proof General logo ]" >
@end ifhtml

A @dfn{proof assistant} is a computerized helper for developing
mathematical proofs.

@dfn{Proof General} is a generic Emacs interface for proof assistants,
developed at the LFCS in the University of Edinburgh.  It works best
under XEmacs, but can also be used with FSF GNU Emacs.

You do not have to be an Emacs militant to use Proof General!  @*

The interface is designed to be very easy to use.  You develop your
proof script in-place rather than line-by-line and later reassembling
the pieces.  Proof General keeps track of which proof steps have been
processed by the prover, and prevents you editing them accidently.  You
can undo steps as usual.

Our aim is provide a powerful and configurable Emacs mode which helps
user-interaction with interactive proof assistants.  Please help us with
this aim!  Configure Proof General for your proof assistant, by adding
features at the generic level wherever possible.  See 
@ref{Adapting Proof General to New Provers}
for more details, and send ideas, comments, patches,
and code to @code{proofgen@@dcs.ed.ac.uk}.

@menu
* Quick start guide::           
* Features of Proof General::   
* Supported proof assistants::  
* Prerequisites for this manual::
@end menu




@node Quick start guide
@section Quick start guide

Proof General may have been installed for you already. If so, when you
visit a proof script file for your proof assistant, you'll find commands
to process the proof script are available from the toolbar, menus, and
keyboard.  Type @kbd{C-h m} to get a list of keys for the current mode.

The proof assistant is automatically started inside Emacs when you ask
for some of the proof script to be processed.  To follow an example use
of Proof General on a LEGO proof, see @pxref{Walkthrough example in LEGO}.

If Proof General has not already been installed, you should insert the
line:
@lisp
        (load "@var{ProofGeneral}/generic/proof-site.el")
@end lisp
into your @file{~/.emacs} file, where @var{ProofGeneral} is the
top-level directory that was created when Proof General was unpacked.

For more details on obtaining and installing Proof General,
see @pxref{Obtaining and Installing Proof General}.


@node Features of Proof General
@section Features of Proof General
@cindex Features
@cindex Why use Proof General?

Why would you want to use Proof General?

Here is an outline of its main features.

@itemize @bullet
@item @i{Simplified communication}@*
The proof assistant's shell is normally hidden from the user.
Communication takes place via two or three buffers.  The @dfn{script
buffer} holds input, the commands to construct a proof.  The @dfn{goals
buffer} displays the current list of subgoals to be solved.  The
@dfn{response buffer} displays other output from the proof assistants.
This means that the user only sees the output from the most recent proof
step, rather than a screen full of output from the proof assistant.
@c Optionally, the goals buffer and script buffer can be identified.

For more details, see @xref{Basic Script Management},
@xref{Script buffers} and @xref{Summary of Proof General buffers}.

@item @i{Script management}@*
Proof General colours proof script regions blue when they have already
been processed by the prover, and colours regions red when the prover is
currently processing them.  The appearance of Emacs buffers always
matches the proof assistant's state. Coloured parts of the buffer cannot
be edited.  Proof General has functions for @emph{asserting} or
@emph{retracting} parts of a proof script, which alters the coloured
regions.

For more details, see @xref{Basic Script Management},
@xref{Script processing commands}.
and @pxref{Advanced Script Management}.
@item @i{Script editing mode}@*
Proof General provides useful facilities for editing proof scripts,
including syntax hilighting and a menu to jump to particular goals,
definitions, or declarations.
Special editing functions send lines of proof script to the proof
assistant, or undo previous proof steps.

For more details, see @pxref{Script editing commands}
and @pxref{Script processing commands}.
@item @i{Toolbar and menus}@*
A script buffer has a toolbar with navigation buttons for processing
parts of the proof script.  A menu provides further functions for
operations in the proof assistant, as well as customization of Proof
General.

For more details, see @pxref{Toolbar commands}, @pxref{Proof assistant
commands}, and @pxref{Customizing Proof General}.

@c not yet
@c @item @i{Proof by pointing}
@end itemize


@node Supported proof assistants
@section Supported proof assistants

Proof General comes ready-customised for these proof assistants:

@itemize @bullet
@item 
@b{LEGO Proof General} for LEGO Version 1.3.1@*
@c written by Thomas Kleymann and Dilip Sequeira.
@c
All features of Proof General are supported.  
See @pxref{LEGO Proof General} for more details.

@item 
@b{Coq Proof General} for Coq Version 6.2@*
@c written by Healfdene Goguen.
@c
All of features of Proof General are supported except multiple files.
See @pxref{Coq Proof General} for more details.

@item 
@b{Isabelle Proof General} for Isabelle 98-1@*
@c written by David Aspinall.
All features of Proof General are supported, except for an external tags
program.  Isabelle Proof General handles theory files as well as ML
(proof script files), and has an extensive theory file editing mode
taken from @uref{http://www.dcs.ed.ac.uk/home/da/Isamode,Isamode}.
See @pxref{Isabelle Proof General} for more details.
@end itemize
Proof General is designed to be generic, so you can adapt it to other
proof assistants if you know a little bit of Emacs Lisp.
@itemize @bullet
@item
@b{Your Proof General} for your favourite proof assistant@*
See @pxref{Adapting Proof General to New Provers}
for more details of how to make Proof General work
with another proof assistant.
@end itemize


@node Prerequisites for this manual
@section Prerequisites for this manual

This manual assumes that you understand a little about using Emacs, for
example, switching between buffers using @kbd{C-x b} and understanding
that key sequences like @kbd{C-x b} mean "control-X followed by b".

The manual also assumes you have a basic understanding of your proof
assistant and the language and files it uses for proof scripts.  But
even without this, Proof General is not useless: you can use the
interface to @emph{replay} proof scripts for any proof assistant without
knowing how to start it up or issue commands, etc.  This is the beauty
of a common interface mechanism.

To get more from Proof General and adapt it to your liking, it helps to
know a little bit about how Emacs lisp packages can be customized via
the Customization mechanism.  It's really easy to use.  See @xref{Easy
customization} and @inforef{Easy customization, ,(xemacs)} for details.

To get the absolute most from Proof General, to improve it or to adapt
it for new provers, you'll need to know a little bit of Emacs lisp.
Emacs is self-documenting, so you can begin from @kbd{C-h} and find out
everything!  Here are some useful commands:

@table @asis
@item @kbd{C-h i}
@code{info}
@item @kbd{C-h m} 
@code{describe-mode}
@item @kbd{C-h b} 
@code{describe-bindings}
@item @kbd{C-h f} 
@code{describe-function}
@item @kbd{C-h v} 
@code{describe-variable}
@end table

Most of this manual covers the user-level view and customization of
Proof General.  Towards the end we consider adapting Proof General to
new proof assistants, and document some of the internals of Proof
General.  The manual concludes with some credits and references.
See the table of contents for details.







@c
@c CHAPTER: Basic Script Management
@c
@node Basic Script Management
@chapter Basic Script Management

This chapter is an introduction to using the script management
facilities of Proof General.  We begin with a quick walkthrough example,
then describe the concepts and functions in more detail.

@menu
* Walkthrough example in LEGO::  
* Proof scripts::               
* Script buffers::              
* Summary of Proof General buffers::               
* Script editing commands::     
* Script processing commands::  
* Toolbar commands::            
* Proof assistant commands::    
@end menu

@node Walkthrough example in LEGO
@section Walkthrough example in LEGO

Here's a short example in LEGO to see how script management is used.
The file you are asked to type below is included in the distribution as
@file{lego/example.l}.  If you're not using LEGO, substitute some lines
from a simple proof for your proof assistant, or consult the example
file provided with Proof General.

First, find a new file by doing @kbd{C-x C-f} and typing as the filename
@file{walkthrough.l}.  This should load LEGO Proof General and the
toolbar and Proof General menus will appear.  This walkthrough is
keyboard based, although you could easily use the toolbar and menu
functions instead.

Now turn on active terminator minor mode by typing @kbd{C-c ;} and
enter:
@lisp
Module Walkthrough Import lib_logic;
@end lisp
The command should be lit in pink (or inverse video if you don't have a
colour display).  As LEGO imports each module, a line will appear in the
minibuffer showing the creation of context marks. Eventually the command
should turn blue, indicating that LEGO has successfully processed
it. Then type (on a separate line if you like):
@lisp
Goal bland_commutes: @{A,B:Prop@} (and A B) -> (and B A);
@end lisp
The goal should be echoed in the goals buffer.
@lisp
Intros;
@end lisp
Whoops! @kbd{C-c C-u} to pretend that didn't happen.
@lisp
intros; andI;
@end lisp
A proof summary will appear in the goals buffer.
@c We could solve the goal by pointing now, but we'll stay with the keyboard.
@lisp
Refine H; intros; Immed; Refine H; intros; Immed;
@end lisp
finishes the Goal. 
@lisp
Save bland_commutes;
@end lisp

Moving the mouse pointer over the locked region now reveals that the
entire proof has been aggregated into a single segment. Suppose we
decide to call the goal something more sensible. Moving the cursor up
into the locked region, somewhere between `Goal' and `Save', we enter
@kbd{C-c u}.  The segment is transferred back into the editing
region. Now we correct the goal name, move the cursor to the end of the
buffer, and type @kbd{C-c RET}.  Proof mode queues the commands for
processing and executes them.




@node Proof scripts
@section Proof scripts
@cindex proof script
@cindex scripting

A @dfn{proof script} is a sequence of commands which construct a proof
in a proof assistant.  Proof General is designed to work with text-based
@i{interactive} proof assistants, where the mode of working is usually a
dialogue between the human and the proof assistant.

Primitive interfaces for proof assistants simply present a shell-like
view of this dialogue: the human repeatedly types commands to the shell
until the proof is completed.  The system responds at each step, perhaps
with a new list of subgoals to be solved, or perhaps with a failure
report.  Proof General manages the dialogue to only show the human the
information which is relevant at each step.

@c Many proof assistants can also process proof scripts held in files

Often we want to keep a record of the proof commands used to prove a
theorem, to build up a library of proved results.  An easy way to store
a proof is to keep a text file which contains a proof script; the proof
assitant usually provides facility to read a proof script from a file
instead of the terminal.  Using the file, we can @dfn{replay} the proof
script to prove the theorem again.
@c Re-playing a proof script is a non-interactive procedure,
@c since it is supposed to succeed.

Using only a primitive shell interface, it can be tedious to construct
proof scripts with cut-and-paste.  Proof General helps out by issuing
commands directly from a proof script file, while it is being written
and edited.  Proof General can also be used conveniently to replay a
proof step-by-step, to see the progress at each stage.
@c developing them in proof script files.

@dfn{Scripting} is the process of building up a proof script file or
replaying a proof.  When scripting, Proof General sends proof commands
to the proof assistant one at a time, and prevents you from editing
commands which have been successfully completed by the proof assistant.
Regions of the proof script are analysed based on syntax and the
behaviour of the proof assistant after each proof command.


@node Script buffers
@section Script buffers
@cindex script buffer
@cindex proof script mode

A @dfn{script buffer} is a buffer displaying a proof script.  Its Emacs
mode is particular to the proof assistant you are using (but it inherits
from @dfn{proof-script mode}).


A script buffer is divided into three regions: @emph{locked},
@emph{queue} and @emph{editing}.  The proof commands
in the script buffer can include a number of
@emph{Goal-save sequences}.

@menu
* Locked queue and editing regions::  
* Goal-save sequences::         
* Active scripting buffer::     
@end menu


@node Locked queue and editing regions
@subsection Locked, queue, and editing regions
@cindex Locked region
@cindex Queue region
@cindex Editing region
@cindex blue text
@cindex pink text


A script buffer is divided into three regions:

@itemize @bullet
@item The @emph{locked} region appears in blue (underlined on monochrome
displays) and contains commands which have been sent to the proof process
and verified. The commands in the locked region cannot be edited.

@item The @emph{queue} region appears in pink (inverse video) and contains
commands waiting to be sent to the proof process. Like those in the
locked region, these commands can't be edited.

@item The @emph{editing} region contains the commands the user is working
on, and can be edited as normal Emacs text.
@end itemize

These three regions appear in the buffer in the order above; that is,
the locked region is always at the start of the buffer, and the editing
region always at the end. The queue region only exists if there is input
waiting to be sent to the proof process.

Proof mode has two fundamental operations which transfer commands
between these regions: @emph{assertion} and @emph{retraction}.
Assertion corresponds to processing proof commands, and makes the locked
region grow.  Retraction corresponds to undoing commands, and makes the
locked region shrink.  @xref{Script processing commands} explains how to
do assertion and retraction.

@node Goal-save sequences
@subsection Goal-save sequences
@cindex goal
@cindex save
@cindex goal-save sequences

A proof script contains a sequence of commands used to prove one or more
theorems.  Proof General assumes that for each proved theorem, a proof
script contains a sequence of commands delimited by a pair of special
commands, known as @code{goal} and @code{save}.  So a proof script has a
series of proofs which look something like this (of course, the exact
syntax will depend on the proof assistant you use):
@lisp
   goal @var{mythm} is @var{G}
   @dots{}
   save theorem @var{mythm}
@end lisp
Proof General recognizes the goal-save sequences in proof scripts.  The
name @var{mythm} can appear in the menu for the proof script
(@pxref{Support for function menus}) to help quickly find a proof, and
once a goal-save region has been fully processed by the proof assistant,
it is treated as atomic when undoing proof steps.  This reflects the
fact that most proof assistants discard the history of a proof once a it
is completed or once a new proof is begun.


@node Active scripting buffer
@subsection Active scripting buffer
@cindex active scripting buffer

You can edit as many script buffers as you want simultaneously, but only
one buffer at a time can be used to process a proof script
incrementally: this is the @dfn{active scripting buffer}.

The active scripting buffer has a special indicator: the word
@code{Scripting} appears in its mode line.

Proof General will give an error message: @code{Cannot have more than
one active scripting buffer!} if you attempt to use the script
processing commands in a new script buffer when there is already an
active scripting buffer which is only partly completed.  If you get this
error message, you must choose either to assert the remainder of the
active buffer, or to retract what has been proved so far, before you can
start scripting in another buffer.

@xref{Switching between proof scripts} for more explanation of this.

@c A completed script buffer is one which is completely blue: the locked
@c region covers the whole buffer, indicating that all the commands been
@c successfully processed by the prover. 


@node Summary of Proof General buffers
@section Summary of Proof General buffers
@cindex shell buffer
@cindex goals buffer
@cindex response buffer
@cindex proof by pointing

Proof General manages several kinds of buffers in Emacs.  Here is a
summary of the different kinds of buffers you will use when developing
proofs.

@itemize @bullet
@item The @dfn{proof shell buffer} is an Emacs shell buffer
 used to run your proof assistant.  Usually it is hidden from view
 (but see @xref{Working directly with the proof shell}).
 Communication with the proof shell takes place via two or three
 intermediate buffers.
@item  A @dfn{script buffer}, as we have explained, is a buffer for editing a
 proof script.  The @dfn{active scripting buffer} is the script buffer
 which is currently being used to send commands to the proof shell.
@item The @dfn{goals buffer} displays the list of subgoals to be
 solved for a proof in progress.  During a proof it is usually
 displayed together with the script buffer.
@c FIXME: change when pbp is added back!
 The goals buffer has facility for @dfn{proof-by-pointing}, although
 this is disabled in Proof General @value{version}.
@item The @dfn{response buffer} displays other output from the proof
 assistant, for example error messages or informative messages.
 The response buffer is displayed whenever Proof General puts
 a new message in it.
@end itemize

Normally Proof General will automatically reveal and hide the goals and
response buffers as necessary during scripting.  However there are ways
to customize the way the buffers are displayed, @pxref{Display
customization}.

The menu @code{Proof General -> Buffers} provides a convenient way to
display or switch to one of the four buffers: active scripting, goals,
response, or shell.

@c When
@c Proof General sees an error in the shell buffer, it will highlight the
@c error and display the buffer automatically.


@c This facility was not added:
@c
@c Optionally, the goals buffer and script buffer can be identified
@c @pxref{Identify goals and response}.  The disadvantage of this is that
@c the goals display can be replaced by other messages, so you must ask for
@c it to be refreshed.  The advantage is that it is simpler to deal with
@c fewer Emacs buffers.



@node Script editing commands
@section Script editing commands

Proof General provides a few functions for editing proof scripts.
Specific proof assistant code may elaborate on these basics.

@findex indent-for-tab-command
@vindex proof-script-indent
Indentation is controlled by the user option @code{proof-script-indent}
@pxref{User options}.  When indentation is enabled, Proof General
will indent lines of proof script with the usual Emacs functions,
particularly @kbd{TAB}, @code{indent-for-tab-command}.

@c FIXME: remove when indentation is fixed.
Unfortunately, indentation in Proof General @value{version} is
somewhat slow and buggy.  Therefore with large proof scripts,
we recommend @code{proof-script-index} is turned off.

Here are the commands for moving around in a proof script,
with their default key bindings:
@kindex C-c C-e
@kindex C-c C-a
@kindex C-c '
@table @kbd
@item C-c C-e
@code{proof-find-next-terminator}
@item C-c C-a
@code{proof-goto-command-start}.
@item C-c '
@code{proof-goto-end-of-locked-interactive}
@end table

@c TEXI DOCSTRING MAGIC: proof-find-next-terminator
@deffn Command proof-find-next-terminator 
Set point after next @samp{@code{proof-terminal-char}}.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-goto-command-start
@deffn Command proof-goto-command-start 
Move point to start of current command.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-goto-end-of-locked-interactive
@deffn Command proof-goto-end-of-locked-interactive 
Switch to @code{proof-script-buffer} and jump to the end of the locked region.
Must be an active scripting buffer.
@end deffn


@node Script processing commands
@section Script processing commands
@kindex C-c C-n
@kindex C-c RET
@kindex C-c u
@kindex C-c C-u

Here are the commands for asserting and retracting portions of the proof
script, together with their default key bindings.

@table @kbd
@item C-c C-n
@code{proof-assert-next-command}
@item C-c C-u
@code{proof-undo-last-successful-command}
@item C-c RET
@code{proof-assert-until-point}
@item C-c u
@code{proof-retract-until-point}
@item C-c b
@code{proof-process-buffer}
@item C-c t
@code{proof-try-command}
@end table

A useful point of @kbd{C-c C-b} is that with a faulty proof script, for
example, a script you are adapting to prove a different theorem, Proof
General will stop exactly where the proof script fails, showing you the
error message and the last processed command.  So you can continue
development from there.



@c TEXI DOCSTRING MAGIC: proof-assert-next-command
@deffn Command proof-assert-next-command &optional unclosed-comment-fun ignore-proof-process-p dont-move-forward for-new-command
Process until the end of the next unprocessed command after point.
If inside a comment, just process until the start of the comment.  
If you want something different, put it inside @var{unclosed-comment-fun}. 
If @var{ignore-proof-process-p} is set, no commands will be added to the queue.
Afterwards, move forward to near the next command afterwards, unless
@var{dont-move-forward} is non-nil.  If @var{for-new-command} is non-nil,
a space or newline will be inserted automatically.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-undo-last-successful-command
@deffn Command proof-undo-last-successful-command &optional no-delete
Undo last successful command at end of locked region.
Unless optional @var{no-delete} is set, the text is also deleted from
the proof script.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-assert-until-point
@deffn Command proof-assert-until-point &optional unclosed-comment-fun ignore-proof-process-p
Process the region from the end of the locked-region until point.
Default action if inside a comment is just process as far as the start of
the comment. If you want something different, put it inside
@var{unclosed-comment-fun}. If @var{ignore-proof-process-p} is set, no commands
will be added to the queue and the buffer will not be activated for
scripting.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-retract-until-point
@deffn Command proof-retract-until-point &optional delete-region
Set up the proof process for retracting until point.
In particular, set a flag for the filter process to call @samp{@code{proof-done-retracting}}
after the proof process has actually successfully reset its state.
If @var{@code{delete-region}} is non-nil, delete the region in the proof script
corresponding to the proof command sequence.
If invoked outside a locked region, undo the last successfully processed
command.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-process-buffer
@deffn Command proof-process-buffer 
Process the current buffer and set point at the end of the buffer.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-try-command
@deffn Command proof-try-command &optional unclosed-comment-fun
Process the command at point, but don't add it to the locked region. 
This will only happen if the command satisfies @code{proof-state-preserving-p}.

Default action if inside a comment is just to go until the start of
the comment. If you want something different, put it inside
@var{unclosed-comment-fun}.
@end deffn



@node Toolbar commands
@section Toolbar commands

The toolbar provides a selection of functions for asserting
and retracting portions of the script, and inserting
"goal" and "save" type commands.

These functions are available only from the toolbar, menu Proof General
-> Scripting, or via @kbd{M-x}.  There are no keybindings for them by
default.


@c TEXI DOCSTRING MAGIC: proof-toolbar-goal
@deffn Command proof-toolbar-goal 
Insert a goal command into the script buffer, issue it to prover.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-retract
@deffn Command proof-toolbar-retract 
Retract entire buffer.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-undo
@deffn Command proof-toolbar-undo 
Undo last successful in locked region, without deleting it.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-next
@deffn Command proof-toolbar-next 
Assert next command in proof to proof process.
Move point if the end of the locked position is invisible.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-use
@deffn Command proof-toolbar-use 
Process the whole buffer
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-restart
@deffn Command proof-toolbar-restart 
Restart scripting via @code{proof-shell-restart}.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-toolbar-qed
@deffn Command proof-toolbar-qed 
Insert a save theorem command into the script buffer, issue it.
@end deffn



@node Proof assistant commands
@section Proof assistant commands
@kindex C-c C-p
@kindex C-c c
@kindex C-c h

There are several commands for interacting with the proof assistant away
from a proof script.  Here are the keybindings and functions.

@table @kbd
@item C-c C-p
@code{proof-prf}
@item C-c c
@code{proof-ctxt}
@item C-c h
@code{proof-help}
@item C-c C-c
@code{proof-interrupt-process}
@item C-c C-v
@code{proof-execute-minibuffer-cmd}
@end table

@c TEXI DOCSTRING MAGIC: proof-prf
@deffn Command proof-prf 
List proof state.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-ctxt
@deffn Command proof-ctxt 
List context.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-help
@deffn Command proof-help 
Print help message giving syntax.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-interrupt-process
@deffn Command proof-interrupt-process 
Interrupt the proof assistant.  @var{warning}! This may confuse Proof General.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-execute-minibuffer-cmd
@deffn Command proof-execute-minibuffer-cmd 
Prompt for a command in the minibuffer and send it to proof assistant.
@end deffn

@c Perhaps, don't explain C-c C-z here. Instead refer to @pxref{Working
@c directly with the proof shell}






@c
@c CHAPTER: Advanced Script Management
@c
@node Advanced Script Management
@chapter Advanced Script Management
@cindex Multiple Files

What we really mean by @emph{advanced} is that Proof General supports
large proof developments. These are typically spread across various
files which depend on each other in some way. Proof General knows enough
about the dependencies to allow script management across multiple files.


@menu
* Switching between proof scripts::  
* View of processed files ::    
* Retracting across files::     
* Asserting across files::      
* Working directly with the proof shell::  
@end menu

@node Switching between proof scripts
@section Switching between proof scripts
@cindex Switching between proof scripts

Basic modularity in large proof developments can be achieved by
splitting proof scripts across various files. Let's assume that you are
in the middle of a proof development. You are working on a soundness
proof of Hoare Logic in a file called@footnote{The suffix may depend of
the specific proof assistant you are using e.g, LEGO's proof script
files have to end with @file{.l}.} @file{HSound.l}. It
depends on a number of other files which develop underlying
concepts e.g. syntax and semantics of expressions, assertions,
imperative programs. You notice that the current lemma is too difficult
to prove because you have forgotten to prove some more basic properties
about determinism of the programming language. Or perhaps a previous
definition is too cumbersome or even wrong.

At this stage, you would like to visit the appropriate file, say
@file{sos.l} and retract to where changes are required. For further
details on how to accomplish this, we refer to @ref{Retracting across
files}. Then, using script management, you want to develop some more
basic theory in @file{sos.l}. Once this task has been completed
(possibly involving retraction across even earlier files) and the new
development has been asserted, you want to swich back to @file{HSound.l}
and replay to the point you got stuck previously.

Some hours (or days) later you have completed the soundness proof and
are ready to tackle new challenges. Perhaps, you want to prove a
property that builds on soundness or you want to prove an orthogonal
property such as completeness.

Proof General lets you do all of this while maintaining the consistency
between proof script buffers and the state of the proof assistant.
However, you cannot have more than one buffer where only a fraction of
the proof script contains a locked region. Before you can employ script
management in  another proof script buffer, you must either fully assert
or retract the current script buffer.

@node View of processed files 
@section  View of processed files

Proof General is aware of all files that the proof assistant has
processed or is currently processing. In fact, it relies on the proof
assistant explicitly telling Proof General whenever it processes a
new file which corresponds@footnote{For example, LEGO generates additional compiled
(optimised) proof script files for efficiency.} to a file containing a proof
script. For further technical
details, @pxref{Handling multiple files}. 

If the current proof script buffer depends on background material from
other files, proof assistants typically process these files
automatically. If you visit such a file, the whole file is locked as
having been processed in a single step. From the user's point of view,
you can only retract but not assert in this buffer. Furthermore,
retraction is only possible to the @emph{beginning} of the buffer.

To be more precise, buffers are locked as soon the proof assistant
notifies Proof General of processing a file different from the
current proof script. Thus, if you visit the file while the proof
assitant is still processing the file, it is already completely locked.
If the proof assistant is not happy with the contents and
complains with an error message, the buffer will still be marked as
having been completely processed. Sorry. You need to visit the
troublesome file, retract (which will always retract to the beginning of 
the file) and debug the problem e.g., by asserting all of the buffer
under the supervision of Proof General, @pxref{Script processing
commands}. 

In case you wondered, inconsistencies may arise when you have unsaved
changes in a proof script buffer and the proof assistant suddenly
decides to automatically process the corresponding file. The good news
is that Proof General detects this problem and flashes up a warning in
the response buffer. You might then want to visit the modified buffer,
save it and retract to the beginning. Then you are back on track.

@node Retracting across files
@section Retracting across files
@cindex Retraction

Make sure that the current script buffer has either been completely
asserted or retracted. Then you can retract proof scripts in a different
file. Simply visit a file that has been processed earlier and retract in
it, using the retraction commands from @ref{Script processing commands}. Apart from removing parts of the locked region in this
buffer, all files which depend on it will be retracted (and thus
unlocked) automatically. Proof General reminds you that now is a good
time to save any unmodified buffers.

@node Asserting across files
@section Asserting across files
@cindex Assertion

Make sure that the current script buffer has either been completely
asserted or retracted. Then you can assert proof scripts in a different
file. Simply visit a file that contains no locked region and assert some
command with the usual assertion commands, @pxref{Script processing
commands}. Proof General reminds you that now is a good time to save any
unmodified buffers. This is particularly useful as assertion may cause
the proof assistant to automatically process other files.


@node Working directly with the proof shell
@section Working directly with the proof shell
@cindex Shell

Occasionally you may want to review the dialogue of the entire session
with the proof assistant, or check that it hasn't done something
unexpected. Experienced users may also want to directly communicate with 
the proof assistant rather than sending commands via the minibuffer,  
@pxref{Proof assistant commands}.

Although the proof shell is usually hidden from view, it is run in a
buffer which provides the usual full editing and history facilities of
Emacs shells (see the package @file{comint.el} distributed with your
version of Emacs). You can switch to it using the menu:

@lisp
  Proof-General -> Switch to buffers -> Proof Shell
@end lisp

@b{Warning:} you can probably cause confusion by typing in the shell
buffer!  Proof General may lose track of the state of the proof
assistant.

Proof General watches the output from the proof assistant to guess when
a file is loaded or when a proof step is taken or undone, but it may not
be guaranteed when the restricted interface is by-passed.  What happens
depends on how complete the communication is between Proof General and
the prover (which depends on the particular instantion of Proof
General).

To resynchronise, you have two options. If you are lucky, it might
suffice to

@table @kbd
@item C-c C-z
move the end of the locked region backwards to the end of the segment
containing the point.
@end table

Otherwise, you will need to restart script management altogether,
@pxref{Toolbar commands}.




@node Support for other Packages
@chapter Support for other Packages

Proof General makes some configuration for other Emacs packages which
provide various useful facilities.  Sometimes this configuration is at
the proof assistant specific level, but we suggest that it should be
made for all proof assistants, as a convention.

The packages currently supported are @code{fume-func},
@code{outline-mode} and @code{etags}.

@menu
* Support for function menus::  
* Support for outline mode::    
* Support for tags::            
@end menu

@node Support for function menus
@section Support for function menus
@vindex proof-goal-with-hole-regexp
@cindex fume-func

The Emacs package @code{fume-func} is a provides the handy facility to
make a menu from the names of entities declared in a buffer.  Proof
General configures @code{fume-func} so that you can quickly jump to
particular proofs in a script buffer.  (This is done with the
configuration variables @code{proof-goal-with-hole-regexp} and
@code{proof-save-with-hole-regexp}.)
@c , @pxref{Proof script mode} for further details.

If you want to use fume-func, you may need to enable it for yourself.
It is distributed with XEmacs but by not enabled by default.  To enable
it you should find the file @file{func-menu.el} and follow the
instructions there.  At the time of writing, the current version of
XEmacs is 20.4, supplied with function menu version 2.45, which suggests
the following code for your @file{.emacs} file:

@lisp
   (require 'func-menu)
   (define-key global-map 'f8 'function-menu)
   (add-hook 'find-file-hooks 'fume-add-menubar-entry t)
   (define-key global-map "\C-cl" 'fume-list-functions)
   (define-key global-map "\C-cg" 'fume-prompt-function-goto)
   (define-key global-map '(shift button3) 'mouse-function-menu)
   (define-key global-map '(meta  button1) 'fume-mouse-function-goto)
@end lisp

If you have another version of Emacs, you should check the
@file{fume-func.el} file supplied with it.

@node Support for outline mode
@section Support for outline mode
@cindex outline mode

Proof General configures Emacs variables (@code{outline-regexp} and
@code{outline-heading-end-regexp}) so that outline minor mode can be
used on proof script files.  The headings taken for outlining are the
"goal" statements at the start of goal-save sequences, 
@xref{Goal-save sequences}.

Use @kbd{M-x outline-minor-mode} to turn on outline minor mode.
Functions for navigating, hiding, and revealing the proof script are
available in menus.

See @inforef{Outline Mode, ,(xemacs)} for more information about
outline mode.



@node Support for tags
@section Support for tags
@cindex tags

A "tags table" is a description of how a multi-file program is broken up
into files.  It lists the names of the component files and the names and
positions of the functions (or other named subunits) in each file.
Grouping the related files makes it possible to search or replace
through all the files with one command.  Recording the function names
and positions makes possible the @kbd{M-.} command which finds the
definition of a function by looking up which of the files it is in.

Some instantiations of Proof General (currently LEGO and Coq) are
supplied with external programs for making tags tables.  Once a tag
table has been made for your proof developments, you can use the Emacs
tags mechanisms to find tags, and complete symbols from tags table.

One useful key binding you might want to make is to set the usual
completion key @kbd{M-tab} to run @code{tag-complete-symbol} to use
completion from names in the tag table.  To set this binding in Proof
General script buffers, put this code in your @file{.emacs} file:
@lisp
(add-hook 'proof-mode-hook
  (lambda () (local-set-key '(meta tab) 'tag-complete-symbol)))
@end lisp
(Since this key binding interfers with a default binding that users may
already have customized, Proof General doesn't do this automatically).

For more information on how to use tags, @inforef{Tags, ,(xemacs)}.



@node Customizing Proof General
@chapter Customizing Proof General
@cindex Customization


There are two kinds of customization for Proof General: it can be
customized for a user's preferences using a particular proof assistant,
or it can be customized by an Emacs expert to add a new proof assistant.
Here we cover the user-level customization for Proof General.

We only consider settings for Proof General itself.  The support for a
particular proof assistant can provide extra customization settings.
See the chapters covering each assistant for details.


@menu
* Easy customization::          
* Display customization::       
* User options::                
* Changing faces::              
* Tweaking configuration settings::  
@end menu

@node Easy customization
@section Easy customization
@cindex Using Customize
@cindex Emacs customization library 

Proof General uses the Emacs customization library extensively to
provide a friendly interface.

You can access a menu of the customization settings for Proof General
via the menu:

@lisp
   Options -> Customize -> Emacs -> External -> Proof General
@end lisp
in XEmacs.  

In FSF Emacs, use the menu:
@c FIXME
@lisp
   Help -> Customize -> Specific group
@end lisp
and type @kbd{proof-general RET}.

The complete set of customization settings will only be availabe after
Proof General has been fully loaded.  Proof General is fully loaded when
you visit a script file for the first time.

When visiting a script file, there is a more direct route to the
settings:
@lisp
   Proof-General -> Customize
@end lisp

Using the customize facility is straightforward.  You can select the
setting to customize via the menus, or with @code{M-x
customize-variable}.  When you have selected a setting, you are shown a
buffer with its current value, and facility to edit it.  Once you have
edited it, you can use the special buttons @var{set}, @var{save} and
@var{done}.  You must use one of @var{set} or @var{save} to get any
effect.  The @var{save} button stores the setting in your @file{.emacs}
file.

Notice that in the customize menus, variable names mentioned later may
be abbreviated by omitting the "@code{proof}-" prefix.  Also, some of
the option settings may have more descriptive names (for example,
@var{on} and @var{off}) than the low-level lisp values (non-@code{nil},
@code{nil}) which are mentioned in this chapter.

For more help, see @inforef{Easy Customization, ,xemacs}.



@node Display customization
@section Display customization
@cindex display customization
@cindex multiple windows
@cindex buffer display customization
@cindex frames
@cindex multiple frames

If you are working on a workstation with a window system, you can use
Emacs to manage several @i{frames} on the display, to keep the goals
buffer displayed in a fixed place on your screen and in a certain font,
for example.  A convenient way to do this is via
@code{special-display-regexps}.


@c TEXI DOCSTRING MAGIC: proof-auto-delete-windows
@defopt proof-auto-delete-windows 
If non-nil, automatically remove windows when they are cleaned.
For example, at the end of a proof the goals buffer window will
be cleared; if this flag is set it will automatically be removed.
If you want to fix the sizes of your windows you may want to set this
variable to @code{nil'} to avoid windows being deleted automatically.
If you use multiple frames, only the windows in the currently
selected frame will be automatically deleted.

The default value is @code{nil}.
@end defopt




@node User options
@section User options
@c Index entries for each option 'concept'
@cindex User options
@cindex Strict read-only
@cindex Query program name
@cindex Dedicated windows
@cindex Remote host
@cindex Toolbar follow mode
@cindex Toolbar disabling
@cindex Proof script indentation
@cindex Indentation
@cindex Remote shell
@cindex Running proof assistant remotely
@c @cindex formatting proof script

Here are the remaining user options for Proof General.  These can be set
via the customization system, via the old-fashioned @code{M-x
edit-options} mechanism, or simply by adding @code{setq}'s to your
@file{.emacs} file.  The first approach is strongly recommended.


@c TEXI DOCSTRING MAGIC: proof-prog-name-ask
@defopt proof-prog-name-ask 
If non-nil, query user which program to run for the inferior process.

The default value is @code{nil}.
@end defopt


@c TEXI DOCSTRING MAGIC: proof-rsh-command
@defopt proof-rsh-command 
Shell command prefix to run a command on a remote host.  
For example,
@lisp
   ssh bigjobs
@end lisp
Would cause Proof General to issue the command @samp{ssh bigjobs isabelle}
to start Isabelle remotely on our large compute server called @samp{bigjobs}.

The protocol used should be configured so that no user interaction
(passwords, or whatever) is required to get going.

The default value is @code{""}.
@end defopt

@c TEXI DOCSTRING MAGIC: proof-toolbar-wanted
@defopt proof-toolbar-wanted 
Whether to use toolbar in proof mode.

The default value is @code{t}.
@end defopt


@c TEXI DOCSTRING MAGIC: proof-toolbar-follow-mode
@defopt proof-toolbar-follow-mode 
Choice of how point moves with toolbar commands.
One of the symbols: @code{locked}, @code{follow}, @code{ignore}.
If @code{locked}, point sticks to the end of the locked region with toolbar commands.
If @code{follow}, point moves just when needed to display the locked region end.
If @code{ignore}, point is never moved after toolbar movement commands.

The default value is @code{locked}.
@end defopt

@c TEXI DOCSTRING MAGIC: proof-window-dedicated
@defopt proof-window-dedicated 
Whether response and goals buffers have dedicated windows.
If t, windows displaying responses from the prover will not
be switchable to display other windows.  This may help manage
your display, but can sometimes be inconvenient, especially
for experienced Emacs users.
Moreover, this option may cause problems with multi-frame
use because of a bug.

The default value is @code{nil}.
@end defopt

@c FIXME needs to mention that without dedicated windows, buffers may be 
@c hidden. Refer to the XEmacs manual on customising buffer display.

@c TEXI DOCSTRING MAGIC: proof-strict-read-only
@defopt proof-strict-read-only 
Whether Proof General is strict about the read-only region in buffers.
If non-nil, an error is given when an attempt is made to edit the
read-only region.  If nil, Proof General is more relaxed (but may give
you a reprimand!)

The default value is @code{15}.
@end defopt


@c TEXI DOCSTRING MAGIC: proof-script-indent
@defopt proof-script-indent 
If non-nil, enable indentation code for proof scripts.
Currently the indentation code can be rather slow for large scripts,
and is critical on the setting of regular expressions for particular
provers.  Enable it if it works for you.

The default value is @code{nil}.
@end defopt

@c TEXI DOCSTRING MAGIC: proof-one-command-per-line
@defopt proof-one-command-per-line 
If non-nil, format for newlines after each proof command in a script.
This option is not fully-functional at the moment.

The default value is @code{nil}.
@end defopt


@c TEXI DOCSTRING MAGIC: proof-splash-inhibit
@defopt proof-splash-inhibit 
Non-nil prevents splash screen display when Proof General is loaded.

The default value is @code{nil}.
@end defopt


@node Changing faces
@section Changing faces

The fonts and colours that Proof General uses are configurable.  If you
alter these through the customize menus, only the particular kind of
display in use (colour window system, monochrome window system, console,
@dots{}) will be affected.

@c TEXI DOCSTRING MAGIC: proof-queue-face
@deffn Face proof-queue-face 
Face for commands in proof script waiting to be processed.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-locked-face
@deffn Face proof-locked-face 
Face for locked region of proof script (processed commands).
@end deffn

@c TEXI DOCSTRING MAGIC: proof-declaration-name-face
@deffn Face proof-declaration-name-face 
Face for declaration names in proof scripts.
Exactly what uses this face depends on the proof assistant.
@end deffn


@c TEXI DOCSTRING MAGIC: proof-tacticals-name-face
@deffn Face proof-tacticals-name-face 
Face for names of tacticals in proof scripts.
Exactly what uses this face depends on the proof assistant.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-error-face
@deffn Face proof-error-face 
Face for error messages from proof assistant.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-warning-face
@deffn Face proof-warning-face 
Face for warning messages.
Warning messages can come from proof assistant or from Proof General itself.
@end deffn

@c Maybe this detail of explanation belongs in the internals,
@c with just a hint here.
The slightly bizarre name of the next face comes from the idea that
while large amounts of output are being sent from the prover, some
messages should be displayed to the user while the bulk of the output is
hidden.  The messages which are displayed may have a special annotation
to help Proof General recognize them, and this is an "eager" annotation
in the sense that it should be processed as soon as it is observed
by Proof General.

@c TEXI DOCSTRING MAGIC: proof-eager-annotation-face
@deffn Face proof-eager-annotation-face 
Face for messages from proof assistant.
@end deffn




@node Tweaking configuration settings
@section Tweaking configuration settings

This section is a note for advanced users.

Configuration settings are the per-prover customizations of Proof
General.  These are not intended to be adjusted by the user.  But
occasionally you may like to test changes to these settings to improve
the way Proof General works.  You may want to do this when a proof
assistant has a flexible proof script language in which one can define
new tactics or even operations, and you want Proof General to recognize
some of these which the default settings don't mention.  So please feel
free to try adjusting the configuration settings and report to us if you
find better default values than the ones we have provided.

The configuration settings appear in the customization group
@code{prover-config}, or via the menu
@lisp
    Proof-General -> Internals ->  Prover Config
@end lisp

One basic example of a setting you may like to tweak is:

@c TEXI DOCSTRING MAGIC: proof-assistant-home-page
@defvar proof-assistant-home-page 
Web address for information on proof assistant
@end defvar

Most of the others are more complicated.  More details of the settings
are given in @xref{Adapting Proof General to New Provers}.  To browse
them, you can look through the customization groups
@code{prover-config}, @code{proof-script} and @code{proof-shell}.  The
group @code{proof-script} contains the configuration variables for
scripting, and the group @code{proof-shell} contains those for
interacting with the proof assistant.

Unfortunately, although you can use the customization mechanism to set
and save these variables, saving them may have no effect because the
default settings are often hard-wired into the proof assistant code.
Ones we expect may need changing appear as proof assistant specific
configurations.  For example, @code{proof-assistant-home-page} is set in
the LEGO code from the value of the customization setting
@code{lego-www-home-page}.  At present there is no easy way to save
changes to other configuration variables across sessions, other than by
editing the source code.  Please contact us if this proves to be a
problem for any variable.





@c
@c  CHAPTER: LEGO Proof General
@c 
@node LEGO Proof General
@chapter LEGO Proof General
@cindex LEGO Proof General

LEGO proof script mode is a mode derived from proof script mode for
editing LEGO scripts. An important convention is that proof script
buffers @emph{must} start with a module declaration. If the proof script
buffer's file name is @file{fermat.l}, then it must commence with a
declaration of the form

@lisp
Module fermat;
@end lisp

If, in the development of the module @samp{fermat}, you require material
from other module e.g., @samp{lib_nat} and @samp{galois}, you need to
specify this dependency as part of the module declaration:

@lisp
Module fermat Import lib_nat galois;
@end lisp

No need to worry too much about effeciency. When you retract back to a
module declaration to add a new import item, LEGO does not actually
retract the previously imported modules. Therefore, reasserting the
extended module declaration really only processes the newly imported
modules.

Using the LEGO Proof General, you never ever need to use administrative
LEGO commands such as @samp{Forget}, @samp{ForgetMark}, @samp{KillRef},
@samp{Load}, @samp{Make}, @samp{Reload} and @samp{Undo} again
@footnote{And please, don't even think of including those in your LEGO
proof script!}. You can concentrate on your actual proof developments.
Script management in Proof General will invoke the appropriate commands
for you. Proving with LEGO has never been easier.

@menu
* LEGO specific commands::      
* LEGO tags::                   
* LEGO customizations::         
@end menu


@node LEGO specific commands
@section LEGO specific commands

In addition to the commands provided by the generic Proof General, see
the previous sections, the LEGO Proof General provides a few extensions.
In proof scripts, there are some abbreviations for common commands:

@table @kbd
@item C-c i   
intros
@item C-c I   
Intros
@item C-c R   
Refine
@end table

@node LEGO tags
@section LEGO tags

The LEGO Proof General provides the program @file{legotags} to generate
tags for LEGO proof scripts. Invoking @samp{legotags *.l} produces a
file @file{TAGS} for all LEGO modules in the current directory. The LEGO
library itself is shipped out with all its modules already being tagged.
See @ref{Support for tags} for further details.


@node LEGO customizations
@section LEGO customizations

We refer to chapter @ref{Customizing Proof General} for an introduction
to the customisation mechanism. In addition to customizations at the
generic level, for LEGO you can also customize:

@c TEXI DOCSTRING MAGIC: lego-tags
@defopt lego-tags 
The directory of the @var{tags} table for the @var{lego} library

The default value is @code{"/usr/lib/lego/lib_Type/"}.
@end defopt

@c TEXI DOCSTRING MAGIC: lego-help-menu-list
@defvar lego-help-menu-list 
List of menu items, as defined in @samp{@code{easy-menu-define}} for @var{lego}
@lisp
  specific help.
@end lisp
@end defvar

@c We don't worry about the following for now. These are too obscure.
@c lego-indent
@c lego-test-all-name

@c We also don't document any of the internal variables which have been
@c set to configure the generic Proof General and which the user should
@c not tamper with

In Xemacs 20.4, LEGO script buffer are coloured (fontified as they say)
by default. To automatically switch on fontification in FSF Emacs 20.2,
you need to set
@vindex lego-mode-hooks
@cindex font-lock colour

@lisp
 (add-hook 'lego-mode-hooks 'turn-on-font-lock)
@end lisp

in your @file{~/.emacs} file.



@node Coq Proof General
@chapter Coq Proof General

Sorry, there is no specific documentation written yet for Coq Proof
General.

If any Coq user would like to contribute, please send a message to
@code{proofgen@@dcs.ed.ac.uk}.

Type @kbd{C-h C-m} to get a list of Coq specific commands and
browse the customize menus to find out what customization
options there are for Coq.

@menu
* Coq specific commands::       
* Coq customizations::          
@end menu

@node Coq specific commands
@section Coq specific commands

@node Coq customizations
@section Coq customizations


@c
@c  CHAPTER: Isabelle Proof General
@c

@node Isabelle Proof General
@chapter Isabelle Proof General
@cindex Isabelle Proof General

Isabelle Proof General includes a mode for editing theory files taken
from David Aspinall's Isamode interface,
@uref{http://www.dcs.ed.ac.uk/home/da/Isamode}.  Detailed documentation
for the theory file mode is included with @code{Isamode}, there are some
notes on the special functions available and customization setttings
below.

@menu
* Theory files::                
* Isabelle specific commands::  
* Isabelle customizations::     
@end menu


@node Theory files
@section Theory files
@cindex Theory files (in Isabelle)
@cindex ML files (in Isabelle)

Isabelle Proof General attempts to lock theory files as well as ML files
when they are loaded.  Theory files are always completely locked or
completely unlocked, because they are processed atomically.

Proof General attempts to load the theory file for a @file{.ML} file
automatically before you start scripting.  This is tricky because
Isabelle's theory loader assumes that @file{.ML} files are always read
together with theory files.  At the moment Proof General uses an altered
version of @code{use_thy} which doesn't load the top-level ML file in
this case.  

@c FIXME: should say something about this:
@c This can cause confusion in the theory loader later,
@c especially with @code{update()}.  To be safe, try to use just the Proof
@c General interface, and report any repeatable problems to
@c @code{isabelle@dcs.ed.ac.uk}.

Compared to Isamode's theory editing mode, some of the functions and key
bindings for interacting with Isabelle have been removed, and two new
functions are available.  

The key @kbd{C-c C-b} (@code{isa-process-thy-file}) will cause Isabelle
to read the theory file being edited.  This causes the file and all its
children (both theory and ML files) to be read.  Any top-level ML file
associated with this theory file is also read.

The key @kbd{C-c C-u} (@code{isa-retract-thy-file}) will retract
(unlock) the theory file being edited.  This unlocks the file and all
its children (theory and ML files); no changes occur in Isabelle itself.


@c TEXI DOCSTRING MAGIC: isa-process-thy-file
@deffn Command isa-process-thy-file file
Process the theory file @var{file}.  If interactive, use @code{buffer-file-name}.
@end deffn

@c TEXI DOCSTRING MAGIC: isa-retract-thy-file
@deffn Command isa-retract-thy-file file
Retract the theory file @var{file}. If interactive, use @code{buffer-file-name}.
@end deffn


@node Isabelle specific commands
@section Isabelle specific commands


@unnumberedsubsec Switching to theory files
@cindex Switching to theory files
@kindex C-c C-o

In Isabelle proofscript mode, @kbd{C-c C-o} (@code{thy-find-other-file})
finds and switches to the associated theory file, that is, the file with
the same base name but extension @file{.thy} swapped for @file{.ML}.

The same function (and keybinding) switches back to an ML file from the
theory file.


@c TEXI DOCSTRING MAGIC: thy-find-other-file
@deffn Command thy-find-other-file &optional samewindow
Find associated .ML or .thy file.
Finds and switch to the associated ML file (when editing a theory file)
or theory file (when editing an ML file).  
If @var{samewindow} is non-nil (interactively, with an optional argument)
the other file replaces the one in the current window.
@end deffn


@node Isabelle customizations
@section Isabelle customizations

Here are some of the user options specific to Isabelle.  You can set
these with the customization mechanism as usual.

@c TEXI DOCSTRING MAGIC: isabelle-web-page
@defvar isabelle-web-page 
URL of web page for Isabelle.
@end defvar


@c @unnumberedsubsec Theory file editing customization

@c TEXI DOCSTRING MAGIC: thy-use-sml-mode
@defopt thy-use-sml-mode 
If non-nil, invoke sml-mode inside "ML" section of theory files.
This option is left-over from Isamode.  Really, it would be more
useful if the script editing mode of Proof General itself could be based 
on sml-mode, but at the moment there is no way to do this.

The default value is @code{nil}.
@end defopt

@c TEXI DOCSTRING MAGIC: thy-indent-level
@defvar thy-indent-level 
Indentation level for Isabelle theory files.  An integer.
@end defvar

@defopt thy-indent-level
Indentation level for Isabelle theory files.  An integer.
@end defopt

@c TEXI DOCSTRING MAGIC: thy-sections
@defvar thy-sections 
Names of theory file sections and their templates.
Each item in the list is a pair of a section name and a template.
A template is either a string to insert or a function. Useful functions are:
@lisp
  @code{thy-insert-header}, @code{thy-insert-class}, @code{thy-insert-default-sort},
  @code{thy-insert-const}, @code{thy-insert-rule}.
@end lisp
The nil template does nothing.
You can add extra sections to theory files by extending this variable.
@end defvar

@c TEXI DOCSTRING MAGIC: thy-template
@defvar thy-template 
Template for theory files.
Contains a default selection of sections in a traditional order.
You can use the following format characters:

%t --- replaced by theory name
%p --- replaced by names of parents, separated by @samp{+} characters
@end defvar

@c ideal for above:
@c @defopt thy-template
@c Template for theory files.
@c Contains a default selection of sections in a traditional order.
@c You can use the following format characters:
@c   @code{%t}  -- replaced by theory name
@c   @code{%p}  -- replaced by names of parents, separated by @code{+}'s
@c @end defopt




@node Adapting Proof General to New Provers
@chapter Adapting Proof General to New Provers

Proof General has about 60 configuration variables which are set on a
per-prover basis to configure the various features.  However, many of
these variables occcur in pairs (typically regular expressions matching
the start and end of some text), and you can begin by setting just a few
variables to get the basic features working.

The configuration variables are declared in the file
@file{generic/proof-config.el}.  Documentation below is based on the
contents of that file.

@menu
* Overview of adding a new prover::            
* Major modes used by Proof General::  
* Menus and user-level commands::  
* Proof script settings::       
* Proof shell settings::        
* Splash screen settings::      
* Goals buffer configuration::  
* Global constants::            
* Handling multiple files::     
@end menu


@node Overview of adding a new prover
@section Overview of adding a new prover

Each proof assistant supported has its own subdirectory under
@var{proof-home-directory}, used to store a root elisp file and any
other files needed to adapt the proof assistant for Proof General.

@c Here we show how a minimal configuration of Proof General works for
@c Isabelle, without any special changes to Isabelle.

Here is how to go about adding support for a new prover.

@itemize @bullet
@item Make a directory called @file{myassistant/} under the Proof General home
directory, to put the specific customization and associated files in.
@item Add a file @file{myassistant.el} to the new directory.
@item Edit @file{proof-site.el} to add a new entry to the
  @var{proof-assistants-table} variable.  The new entry should look like
this:
@lisp
    (myassistant "My New Assistant" "\\.myasst$")
@end lisp    
The first item is used to form the name of the internal variables for
the new mode as well as the directory and file where it loads from.  The
second is a string, naming the proof assistant.  The third item is a
regular expression to match names of proof script files for this
assistant.  See the documentation of @var{proof-assistant-table} for
more details.
@item Define the new modes in @file{myassistant.el}, by looking at 
 the files for the currently supported assistants for example.
 Basically you need to define some modes using @code{define-derived-mode}
 and set the configuration variables.  It's important that your modes
 invoke the callbacks @code{proof-config-done} and
 @code{proof-shell-config-done} once they've set the configuration
 variables.
@end itemize

You could begin by setting minimum number of the variables, then adjust
the settings via the customize menus, under Proof-General -> Internals.


@c TEXI DOCSTRING MAGIC: proof-assistant-table
@defopt proof-assistant-table 
Proof General's table of supported proof assistants.
Extend this table to add a new proof assistant.
Each entry is a list of the form
@lisp
    (@var{symbol} @var{name} @var{automode-regexp})
@end lisp
The @var{name} is a string, naming the proof assistant.
The @var{symbol} is used to form the name of the mode for the
assistant, @samp{SYMBOL-mode}, run when files with @var{automode-regexp}
are visited.  @var{symbol} is also used to form the name of the
directory and elisp file for the mode, which will be
@lisp
    <proof-home-directory>/SYMBOL/@var{symbol}.el
@end lisp
where @samp{<proof-home-directory>/} is the value of the
variable @code{proof-home-directory}.

The default value is @code{((isa "Isabelle" "\\.ML$\\|\\.thy$") (lego "LEGO" "\\.l$") (coq "Coq" "\\.v$"))}.
@end defopt

@node Major modes used by Proof General
@section Major modes used by Proof General

@c TEXI DOCSTRING MAGIC: proof-mode-for-shell
@defvar proof-mode-for-shell 
Mode for proof shell buffers.
Usually customised for specific prover.
Suggestion: this can be set in @code{proof-pre-shell-start-hook}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-response
@defvar proof-mode-for-response 
Mode for proof response buffer.
Usually customised for specific prover.
Suggestion: this can be set in @code{proof-pre-shell-start-hook}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-pbp
@defvar proof-mode-for-pbp 
Mode for proof state display buffers.
Usually customised for specific prover.
Suggestion: this can be set in @code{proof-pre-shell-start-hook}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-script
@defvar proof-mode-for-script 
Mode for proof script buffers.
This is used by Proof General to find out which buffers 
contain proof scripts.
Suggestion: this can be set in the script mode configuration.
@end defvar

@node Menus and user-level commands
@section Menus and user-level commands

@c TEXI DOCSTRING MAGIC: proof-assistant-home-page
@defvar proof-assistant-home-page 
Web address for information on proof assistant
@end defvar
@c TEXI DOCSTRING MAGIC: proof-ctxt-string
@defvar proof-ctxt-string 
Command to display the context in proof assistant.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-help-string
@defvar proof-help-string 
Command to ask for help in proof assistant.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-prf-string
@defvar proof-prf-string 
Command to display proof state in proof assistant.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-command
@defvar proof-goal-command 
Command to set a goal in the proof assistant.  String or fn.
If a string, the format character %s will be replaced by the
goal string. If a function, should return a command string to
insert when called interactively.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-save-command
@defvar proof-save-command 
Command to save a proved theorem in the proof assistant.  String or fn.
If a string, the format character %s will be replaced by the
theorem name. If a function, should return a command string to
insert when called interactively.
@end defvar

@c defgroup proof-script
@node Proof script settings
@section Proof script settings

The following variables should be set before proof-config-done
is called.  These configure the mode for the script buffer,
including highlighting, etc.

@c TEXI DOCSTRING MAGIC: proof-terminal-char
@defvar proof-terminal-char 
Character which terminates a proof command in a script buffer.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-comment-start
@defvar proof-comment-start 
String which starts a comment in the proof assistant command language.
The script buffer's @code{comment-start} is set to this string plus a space.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-comment-end
@defvar proof-comment-end 
String which starts a comment in the proof assistant command language.
The script buffer's @code{comment-end} is set to this string plus a space.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-save-command-regexp
@defvar proof-save-command-regexp 
Matches a save command
@end defvar
@c TEXI DOCSTRING MAGIC: proof-save-with-hole-regexp
@defvar proof-save-with-hole-regexp 
Regexp which matches a command to save a named theorem.
Match number 2 should be the name of the theorem saved.
Used for setting names of goal..save regions and for default
func-menu configuration in proof-script-find-next-goalsave.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-command-regexp
@defvar proof-goal-command-regexp 
Matches a goal command.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-with-hole-regexp
@defvar proof-goal-with-hole-regexp 
Regexp which matches a command used to issue and name a goal.
Match number 2 should be the name of the goal issued.
Used for setting names of goal..save regions and for default
func-menu configuration in proof-script-find-next-goalsave.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-script-next-entity-regexps
@defvar proof-script-next-entity-regexps 
Regular expressions to control finding definitions in script.
This is the list of the form
@lisp
   (@var{anyentity-regexp}
    @var{discriminator-regexp}  ... @var{discriminator-regexp})
@end lisp
The idea is that @var{anyentity-regexp} matches any named entity in the
proof script, on a line where the name appears.  This is assumed to be
the start or the end of the entity.  The discriminators then test
which kind of entity has been found, to get its name.  A
@var{discriminator-regexp} has one of the forms
@lisp
  (@var{regexp} @var{matchno}) 
  (@var{regexp} @var{matchno} @code{backward} @var{backregexp}) 
  (@var{regexp} @var{matchno} @code{forward} @var{forwardregexp})
@end lisp
If @var{regexp} matches the string captured by @var{anyentity-regexp}, then
@var{matchno} is the match number for the substring which names the entity.

If @code{backward} @var{backregexp} is present, then the start of the entity
is found by searching backwards for @var{backregexp}.

Conversely, if @code{forward} @var{forwardregexp} is found, then the end of
the entity is found by searching forwards for @var{forwardregexp}.

Otherwise, the start and end of the entity will be the region matched
by @var{anyentity-regexp}.

This mechanism allows fairly complex parsing of the buffer, in
particular, it allows for goal..save regions which are named
only at the end.  However, it does not parse strings,
comments, or parentheses.

This variable may not need to be set: a default value which should
work for goal..saves is calculated from @code{proof-goal-with-hole-regexp},
@code{proof-goal-command-regexp}, and @code{proof-save-with-hole-regexp}.
@end defvar
@c TEXI DOCSTRING MAGIC: nilproof-goal-command-p nil 
@c TEXI DOCSTRING MAGIC: proof-lift-global
@defvar proof-lift-global 
This function lifts local lemmas from inside goals out to top level.
This function takes the local goalsave span as an argument. Set this
to @samp{nil} of the proof assistant does not support nested goals.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-count-undos-fn
@defvar proof-count-undos-fn 
Compute number of undos in a target segment
@end defvar
@c TEXI DOCSTRING MAGIC: proof-find-and-forget-fn
@defvar proof-find-and-forget-fn 
Function returning a command string to forget back to before its argument span.
The special string @code{proof-no-command} means there is nothing to do.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-hyp-fn
@defvar proof-goal-hyp-fn 
Function which returns cons cell if point is at a goal/hypothesis.
First element of cell is a symbol, @code{goal'} or @code{hyp'}.  The second
element is a string: the goal or hypothesis itself.  This is used
when parsing the proofstate output
@end defvar
@c TEXI DOCSTRING MAGIC: proof-kill-goal-command
@defvar proof-kill-goal-command 
Command to kill a goal.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-global-p
@defvar proof-global-p 
Whether a command is a global declaration.  Predicate on strings or nil.
This is used to handle nested goals allowed by some provers.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-state-preserving-p
@defvar proof-state-preserving-p 
A predicate, non-nil if its argument preserves the proof state.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-activate-scripting-hook
@defvar proof-activate-scripting-hook 
Hook run when a buffer is switched into scripting mode.
The current buffer will be the newly active scripting buffer.

This hook may be useful for synchronizing with the proof
assistant, for example, to switch to a new theory.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-stack-to-indent
@defvar proof-stack-to-indent 
Prover-specific code for indentation.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-parse-indent
@defvar proof-parse-indent 
Proof-assistant specific function for parsing.
Invoked in @samp{proof-parse-to-point}. Must be a
function taking two arguments, a character (the current character)
and a stack reflecting indentation, and must return a stack. The
stack is a list of the form (c . p) where @samp{c} is a character
representing the type of indentation and @samp{p} records the column for
indentation. The generic @samp{proof-parse-to-point} function supports
parentheses and commands. It represents these with the characters
@samp{?(}, @samp{?[} and @samp{@code{proof-terminal-char}}. 
@end defvar



@node Proof shell settings
@section Proof shell settings

The variables in this section are the largest group.  They concern the
proof shell mode.  The first group of variables are hooks invoked at
various points.  The second group of variables are concerned with
matching the output from the proof assistant.

Variables here are put into the customize group @code{proof-shell}.

These should be set in the shell mode configuration, again,
before @code{proof-shell-config-done} is called.

@menu
* Proof shell commands::        
* Settings for matching output from proof process::  
* Hooks and function variables::  
@end menu

@node Proof shell commands
@subsection Commands

@c TEXI DOCSTRING MAGIC: proof-prog-name
@defvar proof-prog-name 
System command to run program name in proof shell.
Suggestion: this can be set in @code{proof-pre-shell-start-hook} from
a variable which is in the proof assistant's customization
group.  This allows different proof assistants to coexist
(albeit in separate Emacs sessions).
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-init-cmd
@defvar proof-shell-init-cmd 
The command for initially configuring the proof process.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-restart-cmd
@defvar proof-shell-restart-cmd 
A command for re-initialising the proof process.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-quit-cmd
@defvar proof-shell-quit-cmd 
A command to quit the proof process.  If nil, send EOF instead.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-cd
@defvar proof-shell-cd 
Command to the proof assistant to change the working directory.
@end defvar

@node Settings for matching output from proof process
@subsection Settings for matching output from proof process
@c TEXI DOCSTRING MAGIC: proof-shell-wakeup-char
@defvar proof-shell-wakeup-char 
A special character which terminates an annotated prompt.
Set to nil if proof assistant does not support annotated prompts.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-first-special-char
@defvar proof-shell-first-special-char 
First special character.
Codes above this character can have special meaning to Proof General,
and are stripped from the prover's output strings.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-prompt-pattern
@defvar proof-shell-prompt-pattern 
Proof shell's value for comint-prompt-pattern, which see.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-annotated-prompt-regexp
@defvar proof-shell-annotated-prompt-regexp 
Regexp matching a (possibly annotated) prompt pattern.
Output is grabbed between pairs of lines matching this regexp.
To help matching you may be able to annotate the proof assistant
prompt with a special character not appearing in ordinary output.
The special character should appear in this regexp, should
be the value of @code{proof-shell-wakeup-char}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-abort-goal-regexp
@defvar proof-shell-abort-goal-regexp 
Regexp matching output from an aborted proof.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-error-regexp
@defvar proof-shell-error-regexp 
Regexp matching an error report from the proof assistant.
We assume that an error message corresponds to a failure
in the last proof command executed.  So don't match
mere warning messages with this regexp.
Moreover, an error message should not be matched as
an eager annotation (see @code{proof-shell-eager-annotation-start})
otherwise it will be lost.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-interrupt-regexp
@defvar proof-shell-interrupt-regexp 
Regexp matching output indicating the assistant was interrupted.
Similar notes apply as for @code{proof-shell-error-regexp}, which see.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-proof-completed-regexp
@defvar proof-shell-proof-completed-regexp 
Regexp matching output indicating a finished proof.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-clear-response-regexp
@defvar proof-shell-clear-response-regexp 
Regexp matching output telling Proof General to clear the response buffer.
This feature is useful to give the prover more control over what output
is shown to the user.  Set to nil to disable.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-start-goals-regexp
@defvar proof-shell-start-goals-regexp 
Regexp matching the start of the proof state output.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-end-goals-regexp
@defvar proof-shell-end-goals-regexp 
Regexp matching the end of the proof state output.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-eager-annotation-start
@defvar proof-shell-eager-annotation-start 
Eager annotation field start.  A regular expression or nil.
An eager annotation indicates to Emacs that some following output
should be displayed immediately and not accumulated for parsing.
Set to nil to disable this feature.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-eager-annotation-end
@defvar proof-shell-eager-annotation-end 
Eager annotation field end.  A regular expression or nil.
An eager annotation indicates to Emacs that some following output
should be displayed immediately and not accumulated for parsing.

The default value is "\n" to match up to the end of the line.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-assumption-regexp
@defvar proof-shell-assumption-regexp 
A regular expression matching the name of assumptions.
@end defvar


@node Hooks and function variables
@subsection Hooks and function variables

@c TEXI DOCSTRING MAGIC: proof-shell-insert-hook
@defvar proof-shell-insert-hook 
Hooks run by @code{proof-shell-insert} before inserting a command.
Can be used to configure the proof assistant to the interface in
various ways (for example, setting the line width of output).
Any text inserted by these hooks will be sent to the proof process
before every command issued by Proof General.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-pre-shell-start-hook
@defvar proof-pre-shell-start-hook 
Hooks run before proof shell is started.
Usually this is set to a function which configures the proof shell
variables.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-handle-error-hook
@defvar proof-shell-handle-error-hook 
Hooks run after an error has been reported in the response buffer.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-process-file
@defvar proof-shell-process-file 
A pair (@var{regexp} . @var{function}) to match a processed file name.

If @var{regexp} matches output, then the function @var{function} is invoked on the
output string chunk. It must return a script file name (with complete
path) the system is currently processing. In practice, @var{function} is
likely to inspect the match data.  If it returns the empty string,
the file name of the scripting buffer is used instead.  If it
returns nil, no action is taken.

Care has to be taken in case the prover only reports on compiled
versions of files it is processing. In this case, @var{function} needs to
reconstruct the corresponding script file name. The new (true) file
name is added to the front of @samp{@code{proof-included-files-list}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-retract-files-regexp
@defvar proof-shell-retract-files-regexp 
A @var{regexp} to match that the prover has retracted across file boundaries.

At this stage, Proof General's view of the processed files is out of
date and needs to be updated with the help of the function
@samp{@code{proof-shell-compute-new-files-list}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-compute-new-files-list
@defvar proof-shell-compute-new-files-list 
Function to update @samp{proof-included-files list}.

It needs to return an up to date list of all processed files. Its
output is stored in @samp{@code{proof-included-files-list}}. Its input is the
string of which @samp{@code{proof-shell-retract-files-regexp}} matched a
substring. In practice, this function is likely to inspect the
previous (global) variable @samp{@code{proof-included-files-list}} and the match
data triggered by @samp{@code{proof-shell-retract-files-regexp}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-process-output-system-specific
@defvar proof-shell-process-output-system-specific 
Set this variable to handle system specific output.
Errors, start of proofs, abortions of proofs and completions of
proofs are recognised in the function @samp{@code{proof-shell-process-output}}.
All other output from the proof engine is simply reported to the
user in the @var{response} buffer.

To catch further special cases, set this variable to a pair of
functions '(condf . actf). Both are given (cmd string) as arguments.
@samp{cmd} is a string containing the currently processed command.
@samp{string} is the response from the proof system. To change the
behaviour of @samp{@code{proof-shell-process-output}}, (condf cmd string) must
return a non-nil value. Then (actf cmd string) is invoked. See the
documentation of @samp{@code{proof-shell-process-output}} for the required
output format.
@end defvar

@node Splash screen settings
@section Splash screen settings

The splash screen can be configured, in a rather limited way.

@c TEXI DOCSTRING MAGIC: proof-splash-time
@defvar proof-splash-time 
Minimum number of seconds to display splash screen for.
The splash screen may be displayed for a couple of seconds longer than
this, depending on how long it takes the machine to initialise proof mode.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-splash-contents
@defvar proof-splash-contents 
Evaluated to configure splash screen displayed when entering Proof General.
If an element is a string or an image specifier, it is displayed
centred on the window on its own line.  If it is nil, a new line is
inserted.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-splash-extensions
@defvar proof-splash-extensions 
Prover specific extensions of splash screen.
These are evaluated and appended to @code{proof-splash-contents}, which see.
@end defvar




@node Goals buffer configuration
@section Goals buffer configuration

The goals buffer configuration will allow configuration of Proof General
for proof by pointing or similar features.  At the moment these settings
are disabled.

@c TEXI DOCSTRING MAGIC: pbp-change-goal
@defvar pbp-change-goal 
Command to change to the goal %s
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-goal-command
@defvar pbp-goal-command 
Command informing the prover that @samp{@code{pbp-button-action}} has been
requested on a goal.
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-hyp-command
@defvar pbp-hyp-command 
Command informing the prover that @samp{@code{pbp-button-action}} has been
requested on an assumption.
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-error-regexp
@defvar pbp-error-regexp 
Regexp indicating that the proof process has identified an error.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-result-start
@defvar proof-shell-result-start 
Regexp matching start of an output from the prover after pbp commands.
In particular, after a @samp{@code{pbp-goal-command}} or a @samp{@code{pbp-hyp-command}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-result-end
@defvar proof-shell-result-end 
Regexp matching end of output from the prover after pbp commands.
In particular, after a @samp{@code{pbp-goal-command}} or a @samp{@code{pbp-hyp-command}}.
@end defvar



@node Global constants
@section Global constants

The settings here are internal constants used by Proof General.
You don't need to configure these for your proof assistant
unless you want to modify or extend the defaults.

@c TEXI DOCSTRING MAGIC: proof-general-name
@defvar proof-general-name 
Proof General name used internally and in menu titles.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-proof-general-home-page
@defopt proof-proof-general-home-page 
Web address for Proof General

The default value is @code{"http://www.dcs.ed.ac.uk/home/proofgen"}.
@end defopt
@c TEXI DOCSTRING MAGIC: proof-universal-keys
@defvar proof-universal-keys 
List of keybindings which for the script and response buffer. 
Elements of the list are tuples (k . f) 
where @samp{k} is a keybinding (vector) and @samp{f} the designated function.
@end defvar



@node Handling multiple files
@section Handling multiple files
@cindex Multiple files

Large proof developments are typically spread across multiple files.
Many provers support such developments by keeping track of dependencies
and automatically processing scripts. Proof General supports this
mechanism. The user's point of view is
explored further in @ref{Advanced Script Management}. Here, we 
describe the more technical nitty gritty. This is what you need to know
when you customise another proof assistant to work with Proof General.

The key idea is that we leave it to the specific proof assistant to
worry about managing multiple files. But whenever the proof assistant
processes or retracts a file it must clearly say so.

@vindex proof-shell-eager-annotation-start
@vindex proof-shell-eager-annotation-end

Proof General considers @var{output} delimited by the the two regualar
expressions @code{proof-shell-eager-annotation-start} and
@code{proof-shell-eager-annotation-end} as being important. It displays
the @var{output} in the Response buffer and analyses their contents further.
Among possibly other important messages characterised by these regular
expressions, the prover must tell the interface whenver it processes a
file and retracts across file boundaries. 


@vtable @code
@item proof-included-files-list
records the file history. Whenever a new file is being processed, Proof
General adds it to the
front of the list. When the prover retracts across file boundaries, this
list is resynchronised. It contains files in canonical truename format.
@inforef{Truenames,,lispref}. You should not set this variable directly.
The generic Proof General will modify @code{proof-included-files-list}
itself. Instead, for a specific proof assistant you need to customise
@code{proof-shell-process-file}. @code{proof-shell-retract-files-regexp} 
and @code{proof-shell-compute-new-files-list}.

@item proof-shell-process-file 
is either nil or a tuple of the form (@var{regexp}, @var{function}). If
@var{regexp} matches a substring of @var{str}, then the function
@var{function} is invoked with input @var{str}. It must return a script
file name (with complete path) the system is currently processing. In
practice, @var{function} is likely to inspect the match
data. @inforef{Match Data,,lispref}. Care has to be taken in case the
prover only reports on compiled versions of files it is processing. In
this case, @var{function} needs to reconstruct the corresponding script
file name. The new (true) file name is then automatically added to the
front of @code{proof-included-files-list} by the generic code.

@item proof-shell-retract-files-regexp
is a regular expression. It indicates that the prover has retracted
across file boundaries. At this stage, Proof General's view of the
processed files is out of date and needs to be updated with the help of
the function @code{proof-shell-compute-new-files-list}.
@end vtable

@ftable @code
@item proof-shell-compute-new-files-list
Takes as argument the current output of the prover. It needs to return
an up to date list of all processed files. Its output is then
automatically stored in
@code{proof-included-files-list} by the generic Proof General. In practice, this function is likely
to inspect the previous (global) variable
@code{proof-included-files-list} and the match data
@inforef{Match Data,,lispref} triggered by @code{proof-shell-retract-files-regexp}.
@end ftable




@node Internals of Proof General
@chapter Internals of Proof General

This chapter sketches some of the internal functions and variables of
Proof General, to help developers who wish to understand or modify the
code.

Most of the documentation below is generated automatically from the
comments in the code.  Because Emacs lisp is interpreted and
self-documenting, the best way to find your way around the source is
inside Emacs once Proof General is loaded.  Read the source files, and
use functions such as @kbd{C-h v} and @kbd{C-h f}.

The code is split into files.  The following sections document the
important files, kept in the @file{generic/} subdirectory.

@menu
* Spans::                       
* Proof General site configuration::  
* Global variables::            
* Proof script mode::           
* Proof shell mode::            
@end menu



@node Spans
@section Spans
@cindex spans
@cindex extents
@cindex overlays

@dfn{Spans} are an abstraction of XEmacs @dfn{extents} used to help
bridge the gulf between FSF Emacs and XEmacs.  In FSF Emacs, spans are
implemented using @dfn{overlays}.

See the files @file{span-extent.el} and @file{span-overlay.el} for the
implementation of the common interface in each case.

@node Proof General site configuration
@section Proof General site configuration
@cindex installation directories
@cindex site configuration

The file @file{proof-site.el} contains the initial configuration for
Proof General for the site (or user) and the choice of provers.

The first part of the configuration is to set
@code{proof-home-directory} to the directory that @file{proof-site.el}
is located in, or to the variable of the environment variable
@code{PROOFGENERAL_HOME} if that is set.

@c TEXI DOCSTRING MAGIC: proof-home-directory
@defvar proof-home-directory 
Directory where Proof General is installed. Ends with slash.
Default value taken from environment variable PROOFGENERAL_@var{home} if set, 
otherwise based on where the file proof-site was loaded from.
You can use customize to set this variable.
@end defvar

@c They're no longer options.
@c The default value for @code{proof-home-directory} mentioned above is the
@c one for the author's system, it won't be the same for you!

Further directory variables allow the files of Proof General to be split
up and installed across a system if need be, rather than under the
@code{proof-home-directory} root.

@c TEXI DOCSTRING MAGIC: proof-images-directory
@defvar proof-images-directory 
Where Proof General image files are installed. Ends with slash.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-info-directory
@defvar proof-info-directory 
Where Proof General Info files are installed.
@end defvar



@cindex mode stub
After defining these settings, we define a @dfn{mode stub} for each
proof assistant enabled.  The mode stub will autoload Proof General for
the right proof assistant when a file is visited with the corresponding
extension.  The proof assistants enabled are the ones listed
in the @code{proof-assistants} setting.

@c TEXI DOCSTRING MAGIC: proof-assistants
@defopt proof-assistants 
Choice of proof assitants to use with Proof General.
A list of symbols chosen from: @code{isa} @code{lego} @code{coq}.
Each proof assistant defines its own instance of Proof General,
providing session control, script management, etc.  Proof General
will be started automatically for the assistants chosen here.
To avoid accidently invoking a proof assistant you don't have,
only select the proof assistants you (or your site) may need.
@var{note}: to change proof assistant, you must start a new Emacs session.

The default value is @code{(isa lego coq)}.
@end defopt

The file @file{proof-site.el} also defines a version variable.

@c TEXI DOCSTRING MAGIC: proof-version
@defvar proof-version 
Version string identifying Proof General release.
@end defvar




@node Global variables
@section Global variables

Global variables are defined in @file{proof.el}.  The same file defines
a few utility functions and some triggers to load in the other files.

@c TEXI DOCSTRING MAGIC: proof-script-buffer
@defvar proof-script-buffer 
The currently active scripting buffer or nil if none.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-buffer
@defvar proof-shell-buffer 
Process buffer where the proof assistant is run.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-goals-buffer
@defvar proof-goals-buffer 
The goals buffer (also known as the pbp buffer).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-buffer-type
@defvar proof-buffer-type 
Symbol indicating the type of this buffer: @code{script}, @code{shell}, or @code{pbp}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-included-files-list
@defvar proof-included-files-list 
List of files currently included in proof process.
Whenever a new file is being processed, it gets added.
When the prover retracts across file boundaries, this list 
is resynchronised. It contains files in canonical truename format
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-proof-completed
@defvar proof-shell-proof-completed 
Flag indicating that a completed proof has just been observed.
@end defvar

The @file{proof.el} also loads @file{proof-config.el} which declares the
proof assistant configuration variables for Proof General,
@xref{Adapting Proof General to New Provers} for details.


@node Proof script mode
@section Proof script mode

The file @file{proof-script.el} contains the main code for proof script
mode, as well as definitions of menus, keybindings, and user-level
functions.

Proof scripts have two important variables for the locked and queue
regions.  These variables are local to each script buffer (although we
only really need one queue span in total rather than one per buffer).

@c TEXI DOCSTRING MAGIC: proof-locked-span
@defvar proof-locked-span 
The locked span of the buffer.
Each script buffer has its own locked span, which may be detached
from the buffer.
Proof General allows buffers in other modes also to be locked;
these also have a non-nil value for this variable.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-queue-span
@defvar proof-queue-span 
The queue span of the buffer.  May be detached if inactive or empty.
@end defvar

Various utility functions manipulate and examine the spans.  An
important one is @code{proof-init-segmentation}.

@c TEXI DOCSTRING MAGIC: proof-init-segmentation
@defun proof-init-segmentation 
Initialise the queue and locked spans in a proof script buffer.
No harm if the spans have already been allocated.
@end defun

For locking files loaded by a proof assistant, we use the next function.

@c TEXI DOCSTRING MAGIC: proof-mark-buffer-atomic
@defun proof-mark-buffer-atomic buffer
Mark @var{buffer} as having been processed in a single step.

If buffer already contains a locked region, only the remainder of the
buffer is closed off atomically.

This works for buffers which are not in proof scripting mode too,
to allow other files loaded by proof assistants to be marked read-only.
@end defun

Atomic locking is instigated by the next function, which uses the
variables @code{proof-included-files-list} documented earlier
(@xref{Handling multiple files} and @xref{Global variables}).

@c TEXI DOCSTRING MAGIC: proof-register-possibly-new-processed-file
@defun proof-register-possibly-new-processed-file file
Register a possibly new @var{file} as having been processed by the prover.
@end defun

Another important function activates scripting for the current script
buffer.  This may involve switching from one scripting buffer to
another.

@c TEXI DOCSTRING MAGIC: proof-activate-scripting
@defun proof-activate-scripting 
Activate scripting for the current script buffer.

The current buffer is prepared for scripting.  No changes are
necessary if it is already in Scripting minor mode. Otherwise, it
will become the current scripting buffer provided the current
scripting buffer has either no locked region or everything in it has
been processed.

If we're changing scripting buffer and the old one is associated with
a file, add it to @code{proof-included-files-list}.

When a new script buffer has scripting minor mode turned on,
the hooks @samp{@code{proof-activate-scripting-hook}} are run.  This can
be a useful place to configure the proof assistant for
scripting in a particular file, for example, loading the
correct theory, or whatever.

Finally, this may be a good time to ask if the user wants to save some
buffers.
@end defun

The next function is the main one used for parsing the proof script
buffer.

@c TEXI DOCSTRING MAGIC: proof-segment-up-to
@defun proof-segment-up-to pos &optional next-command-end
Create a list of (type,int,string) tuples from end of locked region to @var{pos}.
Each tuple denotes the command and the position of its terminator,
type is one of @code{comment}, or @code{cmd}. @code{unclosed-comment} may be consed onto
the start if the segment finishes with an unclosed comment.
If optional @var{next-command-end} is non-nil, we contine past @var{pos} until
the next command end.
@end defun

The function @code{proof-semis-to-vanillas} is used to convert
a parsed region of the script into a series of commands to
be sent to the proof assistant.

@c TEXI DOCSTRING MAGIC: proof-semis-to-vanillas
@defun proof-semis-to-vanillas semis &optional callback-fn
Convert a sequence of terminator positions to a set of vanilla extents.
Proof terminator positions @var{semis} has the form returned by
the function @code{proof-segment-up-to}.
@end defun

The function @code{proof-assert-until-point} is the main one used to
process commands in the script buffer.  It's actually used to implement
the assert-until-point, active terminator keypress, and
find-next-terminator behaviours.  In different cases we want different
things, but usually the information (i.e. are we inside a comment) isn't
available until we've actually run @code{proof-segment-up-to (point)},
hence all the different options when we've done so.

@c TEXI DOCSTRING MAGIC: proof-assert-until-point
@deffn Command proof-assert-until-point &optional unclosed-comment-fun ignore-proof-process-p
Process the region from the end of the locked-region until point.
Default action if inside a comment is just process as far as the start of
the comment. If you want something different, put it inside
@var{unclosed-comment-fun}. If @var{ignore-proof-process-p} is set, no commands
will be added to the queue and the buffer will not be activated for
scripting.
@end deffn

@code{proof-assert-next-command} is a variant of this function.

@c TEXI DOCSTRING MAGIC: proof-assert-next-command
@deffn Command proof-assert-next-command &optional unclosed-comment-fun ignore-proof-process-p dont-move-forward for-new-command
Process until the end of the next unprocessed command after point.
If inside a comment, just process until the start of the comment.  
If you want something different, put it inside @var{unclosed-comment-fun}. 
If @var{ignore-proof-process-p} is set, no commands will be added to the queue.
Afterwards, move forward to near the next command afterwards, unless
@var{dont-move-forward} is non-nil.  If @var{for-new-command} is non-nil,
a space or newline will be inserted automatically.
@end deffn

The main command for retracting parts of a script is
@code{proof-retract-until-point}.

@c TEXI DOCSTRING MAGIC: proof-retract-until-point
@deffn Command proof-retract-until-point &optional delete-region
Set up the proof process for retracting until point.
In particular, set a flag for the filter process to call @samp{@code{proof-done-retracting}}
after the proof process has actually successfully reset its state.
If @var{@code{delete-region}} is non-nil, delete the region in the proof script
corresponding to the proof command sequence.
If invoked outside a locked region, undo the last successfully processed
command.
@end deffn

To clean up when scripting is stopped or the proof assistant exits, we
use the functions @code{proof-restart-buffers}, and
@code{proof-script-remove-all-spans-and-deactivate}.

@c TEXI DOCSTRING MAGIC: proof-restart-buffers
@defun proof-restart-buffers buffers
Remove all extents in @var{buffers} and maybe reset @samp{@code{proof-script-buffer}}.
No effect on a buffer which is nil or killed.  If one of the buffers
is the current scripting buffer, then @code{proof-script-buffer} 
will deactivated.
@end defun

@c TEXI DOCSTRING MAGIC: proof-script-remove-all-spans-and-deactivate
@defun proof-script-remove-all-spans-and-deactivate 
Remove all spans from scripting buffers via @code{proof-restart-buffers}.
@end defun


@c
@c SECTION: Proof Shell Mode
@c
@node Proof shell mode
@section Proof shell mode
@cindex proof shell mode
@cindex comint-mode

The proof shell mode code is in the file @file{proof-shell.el}.  Proof
shell mode is defined to inherit from @code{comint-mode} using
@code{define-derived-mode} near the end of the file.  The bulk of the
code in the file is concerned with sending code to and from the shell,
and processing output for the associated buffers (goals and response).

Clever process handling is a tricky issue.  Proof General attempts to
manage the process strictly, by mainting a queue of commands to send to
the process.  Once a command has been processed, another one is popped
off the queue and sent.

There are several important internal variables which control
interaction with the process.

@c TEXI DOCSTRING MAGIC: proof-shell-busy
@defvar proof-shell-busy 
A lock indicating that the proof shell is processing.
When this is non-nil, @code{proof-shell-ready-prover} will give
an error.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-marker
@defvar proof-marker 
Marker in proof shell buffer pointing to previous command input.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-action-list
@defvar proof-action-list 
A list of
@lisp
  (@var{span},@var{command},@var{action})
@end lisp
triples, which is a queue of things to do.
See the functions @code{proof-start-queue} and proof-exec-loop.
@end defvar

The function @code{proof-shell-start} is used to initialise a shell
buffer and the associated buffers.  

@c TEXI DOCSTRING MAGIC: proof-shell-start
@deffn Command proof-shell-start 
Initialise a shell-like buffer for a proof assistant.

Also generates goal and response buffers.
Does nothing if proof assistant is already running.
@end deffn

The function @code{proof-shell-kill-function} performs the converse
function of shutting things down; it is used as a hook function for
@code{kill-buffer-hook}.  Then no harm occurs if the user kills the
shell directly, or if it is done more cautiously via
@code{proof-shell-exit}.  The function @code{proof-shell-restart} allows
a less drastic way of restarting scripting, other than killing and
restarting the process.

@c TEXI DOCSTRING MAGIC: proof-shell-kill-function
@defun proof-shell-kill-function 
Function run when a proof-shell buffer is killed.
Value for @code{kill-buffer-hook} in shell buffer.
Attempt to shut down the proof process nicely and
clears up all the locked regions and state variables.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-exit
@deffn Command proof-shell-exit 
Query the user and exit the proof process.
This simply kills the @code{proof-shell-buffer} relying on the hook function
to do the hard work.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-shell-bail-out
@defun proof-shell-bail-out process event
Value for the process sentinel for the proof assistant process.
If the proof assistant dies, kill the shell buffer,
ensuring that script buffers are cleaned up neatly.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-restart
@deffn Command proof-shell-restart 
Restart the proof shell by sending the restart command
and clearing all script buffers.
@end deffn

@c
@c INPUT
@c

Input to the proof shell via the queue region is dealt with by
the functions @code{proof-start-queue} and
@code{proof-shell-exec-loop}.    

@c TEXI DOCSTRING MAGIC: proof-start-queue
@defun proof-start-queue start end alist
Begin processing a queue of commands in @var{alist}.
If @var{start} is non-nil, @var{start} and @var{end} are buffer positions in the
active scripting buffer for the queue region.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-exec-loop
@defun proof-shell-exec-loop 
Process the @code{proof-action-list}.

@samp{@code{proof-action-list}} contains a list of (@var{span} @var{command} @var{action}) triples.

If this function is called with a non-empty @code{proof-action-list}, the
head of the list is the previously executed command which succeeded.
We execute (@var{action} @var{span}) on the first item, then (@var{action} @var{span}) on
any following items which have @code{proof-no-command} as their cmd
components.  If a there is a next command, send it to the process.
If the action list becomes empty, unlock the process and remove the
queue region. 

The return value is non-nil if the action list is now empty.
@end defun

A useful utility function for sending a single command to the process is
@code{proof-shell-invisible-command}.  This should be used to implement
user-level functions rather than attempting to manipulate the proof
action list directly.

@c
@c OUTPUT
@c

Two main functions deal with output, @code{proof-shell-process-output}
and @code{proof-shell-process-urgent-message}.  In effect we consider
the output to be two streams intermingled: the "urgent" messages which
have "eager" annotations, as well as the ordinary ruminations from the
prover.  

The idea is to conceal as much irrelevant information from the user as
possible; only the remaining output between prompts and after the last
urgent message will be a candidate for the goal or response buffer.
The variable @code{proof-shell-urgent-message-marker} tracks
the last urgent message seen.

@c TEXI DOCSTRING MAGIC: proof-shell-process-output
@defun proof-shell-process-output cmd string
Process shell output (resulting from @var{cmd}) by matching on @var{string}.
@var{cmd} is the first part of the @code{proof-action-list} that lead to this
output.
This function deals with errors, start of proofs, abortions of
proofs and completions of proofs. All other output from the proof
engine is simply reported to the user in the response buffer
by setting @code{proof-shell-delayed-output} to a cons cell of
(@var{insert} . @var{text}) where @var{text} is the text to be inserted.

To extend this function, set
@code{proof-shell-process-output-system-specific}.

This function - it can return one of 4 things: @code{error}, @code{interrupt},
@code{loopback}, or nil. @code{loopback} means this was output from pbp, and
should be inserted into the script buffer and sent back to the proof
assistant.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-urgent-message-marker
@defvar proof-shell-urgent-message-marker 
Marker in proof shell buffer pointing to end of last urgent message.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-process-urgent-message
@defun proof-shell-process-urgent-message message
Analyse urgent @var{message} for various cases.
Included file, retracted file, cleared response buffer, or
if none of these apply, display.
@end defun

The main processing point which triggers other actions is
@code{proof-shell-filter}.

@c TEXI DOCSTRING MAGIC: proof-shell-filter
@defun proof-shell-filter str
Filter for the proof assistant shell-process.
A function for @code{comint-output-filter-functions}.

Process urgent messages first.  As many as possible are processed,
using the function @samp{@code{proof-shell-process-urgent-messages}}.

Otherwise wait until an annotated prompt appears in the input, then
run @code{proof-shell-process-output} on the output between the new prompt
and the last input (position of @code{proof-marker}) or the last
urgent message (position of @code{proof-shell-urgent-message-marker}),
whichever is later.  For example, in this case:
@lisp
 @var{prompt} @var{input}
 @var{output-1}
 @var{urgent-message}
 @var{output-2}
 @var{prompt}
@end lisp
@code{proof-marker} is set after @var{input} by @code{proof-shell-insert} and
@code{proof-shell-urgent-message-marker} is set after @var{urgent-message}.
Only @var{output-2} will be processed.  For this reason, error
messages and interrupt messages should @strong{not} be considered
urgent messages.

Appropriate action is taken depending on the what
@code{proof-shell-process-output} returns: maybe handle an interrupt, an
error, or deal with ordinary output which is a candidate
for the goal or response buffer.
Ordinary output is only displayed when the proof action list
becomes empty, to avoid a confusing rapidly changing output.
@end defun



















@c
@c
@c CHAPTER: Obtaining and Installing Proof General
@c
@c
@node Credits and References
@chapter Credits and References

@menu
* Credits::                     
* References::                  
@end menu

@node Credits
@unnumberedsec Credits

LEGO Proof General was written by Thomas Kleymann and Dilip Sequeira.

Coq Proof General was written by Healfdene Goguen.

Isabelle Proof General was written by David Aspinall.

The generic base for Proof General was developed by all four of us.

Thomas Kleymann provided the impetus to develop a generic Emacs
interface, following ideas used in Projet CROAP, and with the help of
Yves Bertot.  David Aspinall provided the Proof General name and images.

An early version of this manual was prepared by Dilip Sequeira.  The
present version was written by David Aspinall and Thomas Kleymann.

During the development of Proof General, the following people helped
by providing feedback, testing, or code:
Pascal Brisset,
Rod Burstall, 
Paul Callaghan,
Martin Hofmann,
James McKinna, 
and Markus Wenzel.  Thanks to all of you!


@node References
@unnumberedsec References

Script management as used in Proof General is described in the paper:

@itemize @bullet
@item
Yves Bertot and Laurent Th@'ery. @i{A generic approach to building
user interfaces for theorem provers}. To appear in Journal of
Symbolic Computation.
@end itemize

Proof General has the beginnings of support for proof by pointing,
as described in the document:

@itemize @bullet
@item
Yves Bertot, Thomas Kleymann-Schreiber and Dilip Sequeira. @i{Implementing
Proof by Pointing without a
Structure Editor}. LFCS Technical Report ECS-LFCS-97-368. Also published as Rapport de recherche de
l'INRIA Sophia Antipolis RR-3286 
@end itemize


@c
@c
@c APPENDIX: Obtaining and Installing Proof General
@c
@c
@node Obtaining and Installing Proof General
@appendix Obtaining and Installing Proof General

Proof General has its own
@uref{http://www.dcs.ed.ac.uk/home/proofgen,home page} hosted at
Edinburgh.  Visit this page for the latest news!

@menu
* Obtaining Proof General::     
* Installing Proof General from tarball::  
* Installing Proof General from RPM package::  
* Notes for syssies::           
@end menu


@node Obtaining Proof General
@section Obtaining Proof General

You can obtain Proof General from the URL
@example
@uref{http://www.dcs.ed.ac.uk/home/proofgen/download.html}.
@end example

The distribution is available in three forms
@itemize @bullet
@item A source tarball, @*
@uref{http://www.dcs.ed.ac.uk/home/proofgen/ProofGeneral-latest.tar.gz}
@item A Linux RPM package (for any architecture), @*
@uref{http://www.dcs.ed.ac.uk/home/proofgen/ProofGeneral-latest.noarch.rpm}
@item A developer's tarball, @*
@uref{http://www.dcs.ed.ac.uk/home/proofgen/ProofGeneral-devel-latest.tar.gz}
@end itemize

Both the tarball and the RPM package include the generic elisp code,
code for LEGO, Coq, and Isabelle, installation instructions (reproduced
below) and this documentation.

@c was Installing Proof General from @file{.tar.gz}
@node Installing Proof General from tarball
@section Installing Proof General from tarball

Copy the distribution to some directory @var{mydir}.
Unpack it there. For example:
@example
# cd @var{mydir}
# gunzip ProofGeneral-@var{version}.tar.gz
# tar -xpf ProofGeneral-@var{version}.tar
@end example
If you downloaded the version called @var{latest}, you'll find it
unpacks to a numeric version number.

Proof General will now be in some subdirectory of @var{mydir}.  The name
of the subdirectory will depend on the version number of Proof General.
For example, it might be @file{ProofGeneral-2.0}.  It's convenient to
link it to a fixed name:
@example
# ln -sf ProofGeneral-2.0 ProofGeneral
@end example
Now put this line in your @file{.emacs} file:
@lisp
    (load-file "@var{mydir}/ProofGeneral/generic/proof-site.el")
@end lisp

This command will load @file{proof-site} which sets the Emacs load path
for Proof General and add auto-loads and modes for the assistants below:

@multitable @columnfractions .3 .3 .4
@item       @b{Prover} @tab @b{Extensions} @tab @b{Modes}
@item       Coq    @tab @file{.v}  @tab @code{coq-mode}
@item       LEGO   @tab @file{.l}  @tab @code{lego-mode}
@item       Isabelle @tab @file{.thy},@file{.ML} @tab @code{isa-mode}
@end multitable
When you load a file with one of these extensions, the corresponding
Proof General mode will be entered.  You can also invoke the mode
command directly.

The default names for proof assistant binaries may work on your system.
If not, you will need to set the appropriate variables.  The easiest way
to do this (and most other customization of Proof General) is via the
Customize mechanism, see the menu item:
@example
  Proof-General -> Customize -> @var{Name of Assistant} -> Prog Name
@end example
The Proof-General menu is available from script buffers after 
Proof General is loaded.  To load it manually, type 
@lisp
  M-x load-library RET proof RET
@end lisp

Notice that the customization mechanism is only available in Emacs 20.x
and XEmacs.  If you cannot use customize, simply add a line like this:
@lisp
  (setq isabelle-prog-name "/usr/bin/isabelle FOL")
@end lisp
to your @file{.emacs} file.


@node Installing Proof General from RPM package
@section Installing Proof General from RPM package

To install an RPM package you need to be root.  Then type
@example
# rpm -Uvh ProofGeneral-latest.noarch.rpm
@end example

Now add the line:
@lisp
   (load-file "/usr/share/emacs/ProofGeneral/generic/proof-site.el")
@end lisp
to your @file{.emacs} or the site-wide initialisation file
@file{site-start.el}.


@node Notes for syssies
@section Notes for syssies

Here are some more notes for installing Proof General in more complex
ways.  Only attempt things in this section if you really understand what
you're doing.

@unnumberedsubsec Byte compilation

Compilation of the Emacs lisp files improves efficiency but can
sometimes cause compatibility problems (especially if you use more than
one version of Emacs at the same time).

You can compile Proof General by typing @code{make} in the directory
where you installed it.


@unnumberedsubsec Site-wide installation

If you are installing Proof General site-wide, you can put the
components in the standard directories of the filesystem if you prefer,
providing the variables in @file{proof-site.el} are adjusted
accordingly, @xref{Proof General site configuration}.  Make sure that
the @file{generic} and assistant-specific elisp files are kept in
subdirectories (@file{coq}, @file{isa}, @file{lego}) of
@code{proof-home-directory} so that the autoload directory calculations
are correct.

To prevent every user needing to edit their own @file{.emacs} files, you
can put the @code{load-file} command to load @file{proof-site.el} into
@file{site-start.el} or similar.  Consult the Emacs documention for more
details if you don't know where to find this file.

@unnumberedsubsec Removing support for unwanted provers

You cannot run more than one instance of Proof General at a time: so if
you're using Coq, visiting an @file{.ML} file will not load Isabelle
Proof General, and the buffer remains in fundamental mode.  If there are
some assistants supported that you never want to use, you can adjust the
variable @code{proof-assistants} in @file{proof-site.el} to solve this
problem, @xref{Proof General site configuration}.

@c Via the Customize mechanism, see the menu:
@c @example
@c   Options -> Customize -> Emacs -> External -> Proof General
@c @end example
@c or, after loading Proof General, in a proof script buffer
@c @example
@c   Proof-General -> Customize
@c @end example



@c
@c
@c APPENDIX: Known bugs and workarounds
@c
@c
@node Known bugs and workarounds
@appendix Known bugs and workarounds

We only mention a few important problems here.  The list is not a
description of all bugs and may be out of date.  @*
Please consult the file
@uref{http://www.dcs.ed.ac.uk/home/proofgen/ProofGeneral/BUGS,@file{BUGS}}
in the distribution for more detailed and up-to-date information.  @*
If you discover a problem which isn't mentioned in @file{BUGS}, please
let us know by sending a note to @code{proofgen@@dcs.ed.ac.uk}.

@menu
* Bugs at the generic level::   
* Bugs specific to LEGO Proof General::  
* Bugs specific to Coq Proof General::  
* Bugs specific to Isabelle Proof General::  
@end menu

@node Bugs at the generic level
@section Bugs at the generic level

@unnumberedsubsec Undo in XEmacs

When @code{proof-strict-read-only} is non-nil, ordinary undo in script
buffer can edit the "uneditable region" in XEmacs.  This doesn't happen
in FSFmacs.  Test case: Insert some nonsense text after the locked
region.  Kill the line. Process to the next command.  Press @kbd{C-x u},
nonsense text appears in locked region.

@strong{Workaround:} be careful with undo.

@unnumberedsubsec Font locking and read-only in FSF Emacs

When @code{proof-strict-read-only} is set and font lock is switched on,
spurious "Region read only" errors are given which break font lock.

@strong{Workaround:} turn off @code{proof-strict-read-only}, font lock,
or for the best of all possible worlds, switch to XEmacs.


@unnumberedsubsec  Pressing keyboard quit @kbd{C-g}

Using @kbd{C-g} can leave script management in a mess.  The code is not
properly protected from Emacs interrupts.

@strong{Workaround:} Don't type @kbd{C-g} while script management is
processing.  If you do, use @code{proof-restart-scripting} to restart
the system.

@unnumberedsubsec One prover at a time
You can't use more than one proof assistant at a time in the same Emacs
session.  Attempting to load Proof General for a second prover will
fail, leaving a buffer in fundamental mode instead of the Proof General
mode for proof scripts.

@strong{Workaround:} stick to one prover per Emacs session, make sure
that the proof-assistants variables only enables Proof General for the
provers you need.


@node Bugs specific to LEGO Proof General
@section Bugs specific to LEGO Proof General

@menu
* Retraction and Discharge::    
* Retraction and proving::      
@end menu

@node Retraction and Discharge
@subsection Retraction and Discharge

After a @code{Discharge}, retraction ought to only be possible back to
the first declaration/definition which is discharged. However, LEGO
Proof General does not know that @code{Discharge} has such a non-local
effect. See @ref{Granularity of atomic command sequences} for a proposal
on how to fix this bug.

@strong{Workaround:} retract back to the first declaration/definition
which is discharged.

@node Retraction and proving
@subsection Retraction and proving
@cindex Retraction

Getting retracting right is tricky when working on proofs. 

@unnumberedsubsec Definitions in a proof state 
A thorny issues are local
definitions in a proof state. LEGO cannot undo them explicitly.

@strong{Workaround:} retract back to a command before a definition.

@unnumberedsubsec Normalisation in proofs
Normalisation commands such as @samp{Dnf}, @samp{Hnf} @samp{Normal}
cannot be undone in a proof state by Proof General.

@strong{Workaround:} retract back to the start of the proof.

@unnumberedsubsec Not saving proofs. 
After LEGO has issued a @samp{***
QED ***} you may undo steps in the proof as long as you don't issue a
@samp{Save} command or start a new proof. The LEGO Proof General assumes
that all proofs are terminated with a proper @samp{Save} command.

@strong{Workaround:} Always issue a @samp{Save} command after completing
a proof. If you forget one, you should retract to a point before the
offending proof development.

@node Bugs specific to Coq Proof General
@section Bugs specific to Coq Proof General

@unnumberedsubsec Hard-wired tactics

The collection of tactics which Proof General is aware of is hard-wired.
Thus, user-defined tactics cannot be retracted.

@strong{Workaround:} You may need to retract to the start of the proof.

@unnumberedsubsec Sections

The Coq Proof General does not know about Coq's section mechansim.

@node Bugs specific to Isabelle Proof General
@section Bugs specific to Isabelle Proof General

@unnumberedsubsec Indentation

Isabelle Proof General doesn't support Proof General's indentation
code to indent proof scripts.  In any case, Proof General's
indentation code is somewhat broken.

@strong{Workaround:} indent your script by hand.

@unnumberedsubsec Scripting lanugage limitations

Since Isabelle uses ML as a top-level language for writing
proof-scripts, Proof General may have difficulty understanding scripts
which stray too far away from the standard functions, tactics, and
tacticals.  You will usually notice when a function, or whatever,
doesn't get highlighted as you might expect.  This probably has no
detrimental impact on the interface unless you use your own variants
of the @code{goal} or @code{qed} forms.

@strong{Workaround:} Restrict yourself to standard proof script
functions, or customize some of the variables from @file{isa.el} and
@file{isa-syntax.el} appropriately.



@node Plans and ideas
@appendix Plans and ideas

This section contains some tentative plans and ideas for improving Proof
General.  Please send us contributions to this wish list, or better
still, offers to implement something from it!

@menu
* Granularity of atomic command sequences::  
* Browser mode for script files and theories::  
@end menu

@node Granularity of atomic command sequences
@section Granularity of atomic command sequences
@c @cindex Granularity of Atomic Sequences
@c @cindex Retraction
@c @cindex Goal
@c @cindex ACS (Atomic Command Sequence)

This is a proposal by Thomas Kleymann for generalising the way Proof
General handles sequences of proof commands @pxref{Goal-save sequences},
particularly to make retraction more flexible.

The locked region of a script buffer contains the initial segment of
the proof script which has been processed successfully. It consists of
atomic sequences of commands (ACS). Retraction is supported to the
beginning of every ACS. By default, every command is an ACS. But the
granularity of atomicity can be adjusted for different proof assistants.
This is essential when arbitrary retraction is not supported. Usually,
after a theorem has been proved, one may only retract to the start of
the goal. One needs to mark the proof of the theorem as an ACS.

@vtable @code
@item proof-atomic-sequents-list
is a list of instructions for setting up ACSs. Each instruction is a
list of the form @code{(@var{end} @var{start} &optional
@var{forget-command})}. @var{end} is a regular expression to recognise
the last command in an ACS. @var{start} is a function. Its input is the
last command of an ACS. Its output is a regular expression to recognise
the first command of the ACS. It is evaluated once and the output is
successively matched against previously processed commands until a match
occurs (or the beginning of the current buffer is reached). The region
determined by (@var{start},@var{end}) is locked as an ACS. Optionally,
the ACS is annotated with the actual command to retract the ACS. This is 
computed by applying @var{forget-command} to the first and last command
of the ACS.
@end vtable

@node Browser mode for script files and theories
@section Browser mode for script files and theories

This is a proposal by David Aspinall for a browser window.

A browser window should provide support for browsing script files and
theories.  We should be able to inspect data in varying levels of
detail, perhaps using outlining mechanisms.  For theories, it would be
nice to query the running proof assistant.  This may require support
from the assistant in the form of output which has been specially
marked-up with an SGML like syntax, for example.

A browser would be useful to:
@itemize @bullet
@item Provide impoverished proof assistants with a browser
@item Extend the uniform interface of Proof General to theory browsing 
@item Interact closely with proof script-writing
@end itemize
The last point is the most important. We should be able to integrate a
search mechanism for proofs of similar theorems, theorems containing
particular constants, etc.




@node Function Index
@unnumbered Function and Command Index
@printindex fn

@node Variable Index
@unnumbered Variable and User Option Index
@printindex vr

@node Keystroke Index
@unnumbered Keystroke Index
@printindex ky

@node Index
@unnumbered Index
@printindex cp

@page
@contents
@bye