documents/libman/eplex.tex

109 library is through {\it Eplex Instances}. An eplex instance is an instance
111 {\it solver state} can be associated with each eplex instance, which can be
112 invoked to solve the eplex problem. Declaratively, an eplex instance can be
116 Like other solvers, each eplex instance has its own module. To use an eplex
117 instance, it must first be declared, so that the module can be created.
122 This predicate will initialise an eplex instance {\tt Name}. Once
127 the instance directly in their code. For example:
130    :- eplex_instance(instance).
134 For convenience, the eplex library declares {\tt eplex} as an eplex instance
158 As with all predicates defined for an eplex instance, these constraints
159 should be module-qualified with the name of the eplex instance. In the
160 following they are shown qualified with the {\tt eplex} instance, and with
209 Bounds for variables can be given to an eplex instance via the \verb'$::/2'
246 Note that all the above constraints are local to the eplex instance; they
249 same eplex instance, unless the user explicitly try to merge the constraints
250 from different solvers/eplex instance.
258 In order to solve an eplex problem, the eplex instance must be set up
265     with the eplex instance. Any arithmetic, integrality and bound
266     constraints posted for this eplex instance are collected to create the
285 Here is a simple linear program, handled by the predefined eplex instance 'eplex':
296 The same example using a user-defined eplex instance:
316 Note that if the {\tt eplex} eplex instance is used instead of {\tt
350 section~\ref{eplex-instance-advanced}.
356 \label{eplex-instance-advanced}
359 \label{eplex-instance-solver-info}
370 instance for the variable {\tt Var}. If {\tt What} is {\tt solution} or
379 Retrieve information about solver state associated with the eplex instance.
384 Set a solver option for the eplex instance.
386 Write out the problem in the the eplex instance's solver state to the file
398 and associate the solver with the eplex instance. No solver must already be
399 setup for the eplex instance. The solver state that is setup can only be
433 between the instances, then the solver state for each instance can have a
437 \index{eplex!instance!eplex_instance/1}
439 declare an eplex instance. For some applications, it might be necessary to
442 In this case, the instance name should {\em not} be used to module-qualify
453 Of course, in the above code, the instance name {\tt pool} is already known
498 constraints posted to the eplex instance since the solver was last invoked
534 The code could look as follows (we use the eplex instance in this example):
547 some infeasibilities that for instance could not be detected by a
638 for instance when execution fails across the solver setup, or
640 with the eplex instance, and any outstanding constraints not yet collected
642 eplex instance is reinitialised.
649 for instance when execution fails across the solver setup, or
666 A solver state is set up for the eplex instance {\tt eplex}, to allow
703   collect_from/1}. This is used to specify which, if any, eplex instance
705 instance is specified (as {\tt pool(Instance)}), then the solver state is
706 associated with that instance. If the eplex instance is {\it not\/} to be
707 associated with an eplex instance, {\tt none} should be given as the
709 without the overhead of an eplex instance. The solver state will not
747 an eplex instance. This is done by:
815 In section~\ref{eplex-instance-solver-info}, we discussed how solver state
816 information can be accessed via the eplex instance. Here are the lower
869 represented by an eplex instance, and was not setup as a demon solver
904 with the eplex instance. However, unlike \bipref{eplex_cleanup/0}{../bips/lib/eplex/eplex_cleanup-0.html}, the
1123 To see the output on these channels, do for instance
1195 be executed instead. The user defined handler could for instance change
1507 associated with the specified eplex instance.
1523 associated with the specified eplex instance.