% =====================
% =     Grail 2.0     =
% =====================

% Release Notes:

% 24-10-00 Some minor changes to make the interface to the CGN
%          database more fluid.
% 24-10-00 Added "commit" option to manual axiom link. By pressing
%          <Shift-Button-1> instead of <Button-1> any alternative
%	   axiom links are automatically disregarded.
% 24-10-00 The size of the font for the indices is also changeable
%          in the font option menu.
% 10-10-00 Previewer type selectable. Current choices are 'none',
%          'dvi', 'ps' and 'pdf'. Restructured menus to reflect this
%          more naturally.
% 29-06-00 LaTeX error messages are now piped to stdout instead of
%          /dev/null/
%          Added some missing safeguards for unavailable fonts.
% 20-03-00 Added option for more compact lexical entries.
% 31-01-00 Used workaround for strange working_directory/2 behaviour
%          in SICStus 3.8.1
% 17-03-99 Added support for color selection to the options menu.
%          Colors and fonts are save with the other options.
% 09-03-99 Added support for font selection in the proof net and
%          rewrite window in the options menu. Connectives will
%          resize to match the current font
% 02-03-99 Added option to show linear precedence information to
%          the rewrite window. Modified undo menu item to activate
%          and deactive itself. Changed label output to produce
%          non-filled circles.
% 11-11-98 Added undo function to rewrite window. When rewriting
%          you can undo your manual rewrite steps. 
% 22-09-98 If the file ~/.grail_default_options exists, Grail will
%          assume it contains the user's options. Users can save the
%          current options to this file from the file menu. Options
%          not available from the menu are also saved.
% 21-09-98 Added extra semantics option for choice between functional
%          ((f y) x) and predicate f(x,y) notation.
% 21-09-98 Added preliminary possibility for user-defined preferences.
% 23-06-98 Term tokenization now melts semantic terms before storing
%          them in the lexicon.
% 14-05-98 Updated term and string tokenization. New version also
%          accepts Prolog symbols and tries to correct typos.
% 13-05-98 Made eager label conversions interactive.
% 13-05-98 Label conversion windows now only check if the label
%          is normal/df if the last action was creep or leap.
%          This allows you to continue rewriting after you encounter
%          a normal or df label.
% 12-05-98 Made eager label conversions visible to user. At this
%          point, eager label conversions are not interactive.
% 12-05-98 Improved detection of cycles.
% 08-05-98 Added an indicator of the (estimated) number of links
%          remaining for the current lookup.
% 06-05-98 Removed (too) detailed messages when running in "leap" or
%          "nonstop" mode.
% 27-04-98 Added option of interactive vs. automatic run mode.
% 21-04-98 Moved all string tokenization from Tcl to Prolog.
%          Added special_string/2 declaration to allow user-defined
%          strings to have their own lexical entry.
% 15-04-98 Included proof net and rewrite window. Version is now
%          2.0 beta.
% 03-04-98 Removed Makefile. LaTeX is only called if options were
%          changed or a new parse was performed.
% 01-04-98 When latex_output_format(none) is selected, computation
%          of natural deduction proofs will be suppressed.
% 13-03-98 Added predicate which tests lexical integrity on loading.
%          This will help when you make a typo in the formulas.
% 10-12-97 Made Grail usable without the tcltk or system libraries.
% 17-11-97 Removed mistake in check_continuity/3.
% 13-11-97 Modified the natural deduction routines prevent generation
%          of natural deduction proofs where the final rule is an
%          unnecessary structural rule.
% 13-11-97 Removed most Prolog messages, since for the average user
%          these are not very useful. You can turn these back on by
%          selecting Options/Prolog Messages/Verbose.
% 10-11-97 Added 'Compile Source' option to file menu. This will look
%          in the directory GRAIL_EXTENSIONS_DIR to find the named .ql
%          or .pl file (whichever is newer). 
% 21-10-97 Removed conflict between lazy/transparent declarations.
%          When a lazy constructor occurred in a transparent context,
%          transparency could force eager evalution of this constructor.
% 14-10-97 Added gray colors to options database. Corrected several
%          inconsistent colorings.
% 18-09-97 Mistake with input of unary/binary indexes corrected. More
%          consistent treatment of new indexes.
% 04-09-97 Support for CLP over finite domains added. See
%          ./fragments/constr.pl for an example. Interaction with
%          postulate and analysis window is not fully supported. 
%          Worried about interaction between constraints and closed set.
% 29-08-97 Environment variables GRAIL_FRAGMENTS_DIR and GRAIL_TEXOUT_DIR 
%          can be set to override the default directories for both the
%          fragments (./fragments) and the LaTeX output (.)
% 07-08-97 Beta version released for ESSLLI'97