===============================================================================
Changes between toolset releases January 2010 and July 2010:
===============================================================================

 General:
   - developed new graphical user interface mcrl2-gui. Use of this tool is
     recommended above using squadt.
   - move to CMake build system. The bjam build system is still included, but
     not actively maintained. It will be removed in the January 2011 release.
   - increase the amount of generated code.
   - more extensive testing

 New functionality:
   - the language now supports function updates for functions of arity 1. It is
     now allowed to write f[d -> e] for a function f: D -> E, with d in D and
     e in E. The meaning is that (f[d -> e])(x) = e if x == d, and f(x)
     otherwise.

 Deprecated tools:
   - squadt is deprecated. It will be removed in the January 2011 release. We
     recommend using mcrl2-gui instead.

 Known issues:
   - ltsview and ltsgraph do not work when started from SQuADT in Windows 7 and
     Windows Vista; if started directly they do function properly. Using
     mcrl2-gui there are no problems.

===============================================================================
Changes between toolset releases January 2009 and January 2010:
===============================================================================

 General:
   - developed a new data and process library and adapted most tools and 
     libraries to use it. Ultimately the classes in core will all be replaced
     such that core will become obsolete.
   - introduced new tool classes and adapted all tools to it, leading to uniform
     command line interfaces for all tools.
   - adapted the user interface of mcrl2i.
   - bisimulation reduction algorithms are much faster.
   
 New functionality:
   - divergence preserving branching bisimulation has been implemented.
   - lps2lts can search for divergences, and generated traces to divergent
     states.
   - lps2lts can generate a state space steered by the first argument of
     actions (which must be a natural number). Only transitions with the
     lowest number will be taken. It is also possible to do a random walk
     in this way.
   - ltsgraph can display transition systems in 3d.
   - lps2pbes now properly supports the use of sorts in the modal formula that
     were defined under alias in the lps.
 
 The following tools have been marked stable:
   - grape: a graphical process editor.
   - mcrl2i: an mCRL2 interpreter that can be used for evaluating data
     expressions.
   - pbesconstelm: apply constant parameter elimination to a pbes.
   - pbesparelm: apply parameter elimination to a pbes.
   - lpsparunfold: unfold a set of given parameters in an lps. (Similar to the
     muCRL tool structelm).
   - lysa2mcrl2: convert a security protocol specified in Typed LySa to mCRL2.
   - txt2lps: read a textual description of a linear process into a binary lps
     file. Rejects anything that is not linear.
 
 The following tools have been added (but are marked experimental):
   - lpsbisim2pbes: encode process equivalences of two linear processes into a
     pbes.
   - lts2lps: convert a labelled transition system into an lps.
   - pbespareqelm: eliminate equivalence relations between parameters of a pbes.
   - pbespgsolve: solve a pbes using a parity game solver algorithm.
     (Contributed by Maks Verver).

The following tools have been removed:
   - mcrl2pp
   - pbessolve

 Notes:
   - SQuADT specific:
     + The tool catalog must be regenerated to add newly connected tools;
       to do this manually remove .squadt/tool_catalog in the home directory.
   - the CMake build system is provided as an alternative to boost build, but
     it is still experimental.
       
 Known issues:
   - ltsview and ltsgraph do not work when started from SQuADT in Windows 7 and
     Windows Vista; if started directly they do function properly.

===============================================================================
Changes between toolset releases July 2008 and January 2009:
===============================================================================

 General:
   - compatible with LTSmin toolset 1.1 van de Universiteit Twente
   - added support for importing LTSes from DOT format
   - extended mCRL2 LTS storage format to include extra information such data
     and parameter specifications. This new format uses the .lts suffix.
   - support for rational numbers (as part of sort Real):
     + rational numbers can be created using the division operator /
     + rational numbers can be converted to integers by means of functions
       floor, ceil and round
   - comparison operations <, <=, >= and > are now defined on all standard
     data types (including structured sorts)
   - sets and bags data structures have been reimplementated to better support
     the use of finite sets and bags. By guaranteeing a unique representation
     of finite sets/bags it is now no longer a problem to generate state spaces
     of processes with finite sets/bags as parameters, for instance.
   - numerous small improvements to tools and underlying infrastructure
   - lots of bug fixes

 Renamed tools:
   - formcheck is now called formulacheck

 New functionality:
   - ltsgraph is completely reimplemented and now uses OpenGL for rendering
   - ltsgraph, ltsview, diagraphica now support all LTS formats supported by
     the LTS library

 New tools:
   - pbesparelm: removes unused parameters from a PBES.
   - pbesconstelm: removes constant parameters from a PBES.

===============================================================================
Changes between toolset releases January 2008 and July 2008:
===============================================================================

 General:
   - improved command line interfaces and help information:
     + simplified interfaces of most tools, especially mcrl22lps, lps2lts,
       lps2torx, ltscompare, ltsmin, ltsconvert, tracepp and formcheck
     + improved consistency among tools
     + adherence to the GNU standard for command line interfaces
     + removed the undocumented feature that the argument '-' can be used
       for reading from standard input in or writing to standard output
     + improved error handling of loading and saving binary files
   - added manual pages for tools
   - changed SVC library license from the
     GNU General Public License, version 2 (or newer), to the
     GNU Lesser General Public License, version 2.1 (or newer).
   - libraries and header files are installed
   - improvements to existing tool and library documentation
   - improved regression testing
   - lots of bug fixes

 Added tools:
   - txt2pbes: translates a textual PBES specification to the binary format

 Removed tools:
   - pbes2bes: most functionality is incorporated in pbes2bool

 Renamed tools:
   - lpsdecluster is now called lpssuminst
   - lpsformcheck is now called formcheck

 Performance improvements:
   - improved performance of lpspp and pbespp for specifications
     involving many variable declarations
   - improved average case performance of div and mod calculations by
     a factor of 2
   - increased power of enumeration involving conditions on list length,
     e.g. enumerating all lists l such that #l == 2 or #l <= 2
   - lpssuminst: summands with a false condition are filtered out
   - lpssumelm: more time-efficient on specifications involving large
     conditions
   - squadt: more time-efficient initialisation process

 New functionality:
   - ltsview: added new option for marking states: mark separately for
     every mark rule
   - ltscompare: added comparison using simulation preorder/equivalence
   - ltsconvert: added minimisation modulo simulation equivalence
   - pbes2bool, lpsactionrename, diagraphica: functional improvements
   - lpssuminst: added (option -t/--tau) which only instantiates tau summands
   - formcheck: now also works with PBESes or without a context specification

 Notes:
   - LPS or PBES files produced with the previous release cannot be used
     anymore. They need to be regenerated using the tools in this release.
   - SQuADT specific:
     + The tool catalog must be regenerated to add newly connected tools;
       to do this manually remove .squadt/tool_catalog in the home directory.
     + Old project files cannot be loaded due to a limitation of the old
       format, automatic conversion is not possible so projects must be
       recreated manually.

===============================================================================
Changes between toolset releases July 2007 and January 2008:
===============================================================================

 General:
   - Numerous bug fixes.
   - Added documentation for all libraries and tools on the website.

 Added tools:
   - chi2mcrl2: translates a subset of Chi to mCRL2
   - lpsactionrename: selectively renames or hides actions in linear processes
   - pbesrewr: applies the rewriter to simplify data expressions in PBESes

 Removed tools:
   - lpsdataelm (its functionality has been integrated in other tools)

 New functionality:
   - Added full support for the verification of modal formulas with data using
     lps2pbes and pbes2bool.
   - Improved handling of time in the lineariser (mcrl22lps). Sometimes this
     slows the lineariser down. Added flags to suppress time if needed.
   - Improvement of the output of the pretty printers (lpspp and pbespp) that
     print linear processes and parameterised boolean equation systems.
   - Added simulation support to ltsview and improved its layout.
   - Functionality of sim is the same as that of xsim (as far as allowed with
     a command line interface).
   - Migrated from CVC Lite to CVC3 as supported external SMT-solver.

 Notes:
   - LPS or PBES files produced with the previous release cannot be used
     anymore. They need to be regenerated using the tools in this release.
   - SQuADT specific:
     + The tool catalog must be regenerated to add newly connected tools;
       to do this manually remove .squadt/tool_catalog in the home directory.
     + Old project files cannot be loaded due to a limitation of the old
       format, automatic conversion is not possible so projects must be
       recreated manually.
