documents/libman/repair.tex

202 \index{conflict constraint}
203 {\em conflict constraint}.
217 When the constraint goes into conflict, it will show up in the
218 conflict set denoted by {\bf ConflictSet}, from where it can be
224 a variable in which case the system returns a conflict set handle that can
230 Note that using different conflict sets for different groups of constraints
236 If this is used, {\bf ConflictData} will appear in the conflict
250 conflict for the first time. If {\bf Constraint} is a finite-domain
272 conflict sets.
273 Typically, a search algorithm examines the conflict set(s) and attempts
275 When all conflict sets are empty, a solution is found.
278 \index{conflict variables}
280 When a variable becomes untenable, it appears in the set of conflict
294 \index{conflict constraints}
296 When a repair constraint goes into conflict (i.e.\ when it does not satisfy
297 the tentative assignment of its variables), it appears in a conflict set,
299 This primitive returns the list of all current conflict constraints
300 in the given conflict set.
301 {\bf ConflictSet} is the conflict set name (or handle) which has
307 and are currently in conflict.
309 At least one variable within a conflict constraint must be reassigned
318 Note that any repair action can change the conflict set,
320 a change has been made, in order to obtain an up-to-date conflict set.
325 The set of variables within the conflict constraints.
334 %propagation of this constraint is delayed until it becomes a {\em conflict
421 We then observe the result by retrieving the conflict sets:
456 Now the constraint \verb+Y #\= Z+, is in conflict since Y is now 3 and Z has the
460 As a result Z becomes a conflict variable since its tentative value (3)
462 conflict constraint set because Z has no valid tentative assignment.
464 The constraint \verb+Y #\= X+ is not affected, it neither goes into conflict
479     ( conflict_vars([C|_]) ->       % label conflict
484         deleteffc(Var,Vars, _),     %  the conflict constraint
493 or constraints in conflict.
510 possible to repair some conflict constraints by changing tentative