ConstraintSystem.Mode Property

Solver Foundation 3.0

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

Gets or sets the debug mode for a solver.

Namespace:  Microsoft.SolverFoundation.Solvers
Assembly:  Microsoft.Solver.Foundation (in Microsoft.Solver.Foundation.dll)

public ConstraintSystem..::..ModelConstructionMode Mode { get; set; }

If the solver is in a debug mode, the solver searches for conflicts after a constraint is added.

The following code demonstrates how to use the ConstraintSystem object to solve the Zebra logic puzzle. For more examples, see Samples for Solver Foundation.

delegate CspTerm NamedTerm(string name);

public static void Zebra() {
  ConstraintSystem S = ConstraintSystem.CreateSolver();
  var termList = new List<KeyValuePair<CspTerm, string>>();

  NamedTerm House = delegate(string name) {
    CspTerm x = S.CreateVariable(S.CreateIntegerInterval(1, 5), name);
    termList.Add(new KeyValuePair<CspTerm, string>(x, name));
    return x;

  CspTerm English = House("English"), Spanish = House("Spanish"),
    Japanese = House("Japanese"), Italian = House("Italian"),
    Norwegian = House("Norwegian");
  CspTerm red = House("red"), green = House("green"),
    white = House("white"),
    blue = House("blue"), yellow = House("yellow");
  CspTerm dog = House("dog"), snails = House("snails"),
    fox = House("fox"),
    horse = House("horse"), zebra = House("zebra");
  CspTerm painter = House("painter"), sculptor = House("sculptor"),
    diplomat = House("diplomat"), violinist = House("violinist"),
    doctor = House("doctor");
  CspTerm tea = House("tea"), coffee = House("coffee"),
    milk = House("milk"),
    juice = House("juice"), water = House("water");

    S.Unequal(English, Spanish, Japanese, Italian, Norwegian),
    S.Unequal(red, green, white, blue, yellow),
    S.Unequal(dog, snails, fox, horse, zebra),
    S.Unequal(painter, sculptor, diplomat, violinist, doctor),
    S.Unequal(tea, coffee, milk, juice, water),
    S.Equal(English, red),
    S.Equal(Spanish, dog),
    S.Equal(Japanese, painter),
    S.Equal(Italian, tea),
    S.Equal(1, Norwegian),
    S.Equal(green, coffee),
    S.Equal(1, green - white),
    S.Equal(sculptor, snails),
    S.Equal(diplomat, yellow),
    S.Equal(3, milk),
    S.Equal(1, S.Abs(Norwegian - blue)),
    S.Equal(violinist, juice),
    S.Equal(1, S.Abs(fox - doctor)),
    S.Equal(1, S.Abs(horse - diplomat))
  bool unsolved = true;
  ConstraintSolverSolution soln = S.Solve();

  while (soln.HasFoundSolution) {
    unsolved = false;
    StringBuilder[] houses = new StringBuilder[5];
    for (int i = 0; i < 5; i++)
      houses[i] = new StringBuilder(i.ToString());
    foreach (KeyValuePair<CspTerm, string> kvp in termList) {
      string item = kvp.Value;
      object house;
      if (!soln.TryGetValue(kvp.Key, out house))
        throw new InvalidProgramException(
                    "can't find a Term in the solution: " + item);
      houses[(int)house - 1].Append(", ");
      houses[(int)house - 1].Append(item);
    foreach (StringBuilder house in houses) {
  if (unsolved)
    System.Console.WriteLine("No solution found.");
"Expected: the Norwegian drinking water and the Japanese with the zebra.");