SWI-Prolog 5.4.2/XPCE 6.4.0 stable release

Although there are still various issues  with the current development it
is decided to call it 5.4.0. This   version  is more stable than 5.2.13,
the remaining issues do not  involve  core   components  and  we  do not
anticipate incompatible changes while resolving them.


New features in 5.4.x relative to 5.2.x and their status
========================================================

  * Attributed variables.

  * Coroutining.

  * Global variables

  * Infinite terms (cyclic terms)
    Incomplete but useable.

    Supported: =/2, ==/2, @>/2 (and friends), copy_term/2, =../2,
               duplicate_term/2, ground/2, dif/2, when/2, term_variables/2,
	       numbervars/3, hash_term/3, findall/3, bagof/3, setof/3,
	       recorded database.

  * CHR constraint language support

  * integer bounds constraint library (clp/bounds.pl) (a subset if CLP(fd)).

  * JPL: Integrated Java/Prolog interface package
    Does not yet support MacOS and various (notably COFF based) systems.


Patches in 5.4.2 relative to 5.4.1
==================================

  * Bug in garbage collector handling `trailed assignments' used by setarg/3,
    attributed variables and backtrackable global variables.  Causes
    incorrect results rather than crashes.

  * Bug in parser reading */* (interpreted as comment)

  * Added strip_module/3 as built-in.


Packages
========

  (none)


Incompatible changes

  (none)
