model "Disjunctive scheduling with settle_disjunction"
uses "kalis"

 declarations
  NBTASKS = 5
  TASKS = 1..NBTASKS                     ! Set of tasks
  DUR: array(TASKS) of integer           ! Task durations
  DUE: array(TASKS) of integer           ! Due dates
  WEIGHT: array(TASKS) of integer        ! Weights of tasks
  start: array(TASKS) of cpvar           ! Start times
  tmp: array(TASKS) of cpvar             ! Aux. variable
  tardiness: array(TASKS) of cpvar       ! Tardiness
  twt: cpvar                             ! Objective variable
  zeroVar: cpvar                         ! 0-valued variable
  Strategy: array(range) of cpbranching  ! Branching strategy
  Disj: set of cpctr                     ! Disjunctions
 end-declarations

 DUR :: [21,53,95,55,34]
 DUE :: [66,101,232,125,150]
 WEIGHT :: [1,1,1,1,1]

 setname(twt, "Total weighted tardiness")
 zeroVar = 0
 setname(zeroVar, "zeroVar")

 forall (t in TASKS) do
  start(t) >= 0
  setname(start(t), "Start("+t+")")
  tmp(t) = start(t) + DUR(t) - DUE(t)
  setname(tardiness(t), "Tard("+t+")")
  tardiness(t) = maximum({tmp(t),zeroVar})
 end-do

 twt = sum(t in TASKS) (WEIGHT(t) * tardiness(t))

 ! Create the disjunctive constraints
 forall(t in 1..NBTASKS-1, s in t+1..NBTASKS)
  (start(t) + DUR(t) <= start(s)) or
  (start(s) + DUR(s) <= start(t))

 ! Define the branching strategy
 Strategy(1):= settle_disjunction
 Strategy(2):= split_domain(KALIS_LARGEST_MIN,KALIS_MIN_TO_MAX)
 cp_set_branching(Strategy)

 ! Solve the problem
 if not(cp_minimize(twt)) then
  writeln("Problem is inconsistent")
  exit(0)
 end-if

 forall (t in TASKS)
  writeln("[", getsol(start(t)), "==>",
          getsol(start(t)) + DUR(t), "]:\t ",
	  getsol(tardiness(t)), "  (", getsol(tmp(t)), ")")
 writeln("Total weighted tardiness: ", getsol(twt))

end-model