public SATVariable(Proposition proposition)
{
Proposition = proposition;
PositiveClauses = new List <ushort>();
NegativeClauses = new List <ushort>();
PredeterminedValue = false;
DeterminationStatus = DeterminationState.Floating;
}
/// <summary>
/// Creates a Literal representing the negation of the proposition
/// </summary>
/// <param name="p">Proposition to negate</param>
public static Literal Not(Proposition p)
{
if (p.IsConstant)
{
return((bool)p ? Proposition.False : Proposition.True);
}
return(Problem.Current.Negation(p));
}
/// <summary>
/// Make a symmetric predicate
/// This will enforce that predicate(a, b) == predicate(b, a)
/// </summary>
/// <typeparam name="T">Argument type</typeparam>
/// <param name="name">Name of the predicate</param>
/// <returns>The predicate object, i.e. a function from arguments to Propositions</returns>
public static Func <T, T, Proposition> SymmetricPredicate <T>(string name) where T : IComparable
{
return((arg1, arg2) =>
{
if (arg1.CompareTo(arg2) > 0)
{
return Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg2, arg1));
}
return Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg1, arg2));
});
}
/// <summary>
/// Make a symmetric, reflexive predicate
/// This will enforce that predicate(a, b) == predicate(b, a)
/// </summary>
/// <typeparam name="T">Argument type</typeparam>
/// <param name="name">Name of the predicate</param>
/// <returns>The predicate object, i.e. a function from arguments to Propositions</returns>
// ReSharper disable once UnusedMember.Global
public static Func <T, T, Proposition> SymmetricTransitiveRelation <T>(string name) where T : IComparable
{
return((arg1, arg2) =>
{
var diff = arg1.CompareTo(arg2);
if (diff > 0)
{
return Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg2, arg1));
}
if (diff == 0)
{
return Proposition.True;
}
// diff < 0
return Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg1, arg2));
});
}
/// <summary>
/// Creates a Literal representing the negation of the proposition
/// </summary>
/// <param name="proposition">Proposition to negate</param>
public Negation(Proposition proposition)
{
this.Proposition = proposition;
}
/// <summary>
/// Test the truth of the specified literal within the model
/// </summary>
public bool this[Proposition p]
{
get => IsTrue(p);
/// <summary>
/// Make a binary predicate
/// </summary>
/// <typeparam name="T1">Type for argument 1</typeparam>
/// <typeparam name="T2">Type for argument 2</typeparam>
/// <param name="name">Name of the predicate</param>
/// <returns>The predicate object, i.e. a function from arguments to Propositions</returns>
public static Func <T1, T2, Proposition> Predicate <T1, T2>(string name)
{
return((arg1, arg2) => Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg1, arg2)));
}
/// <summary>
/// Make a 5-argument predicate
/// </summary>
/// <typeparam name="T1">Type for argument 1</typeparam>
/// <typeparam name="T2">Type for argument 2</typeparam>
/// <typeparam name="T3">Type for argument 3</typeparam>
/// <typeparam name="T4">Type for argument 4</typeparam>
/// <typeparam name="T5">Type for argument 5</typeparam>
/// <param name="name">Name of the predicate</param>
/// <returns>The predicate object, i.e. a function from arguments to Propositions</returns>
// ReSharper disable once UnusedMember.Global
public static Func <T1, T2, T3, T4, T5, Proposition> Predicate <T1, T2, T3, T4, T5>(string name)
{
return((arg1, arg2, arg3, arg4, arg5) => Proposition.MakeProposition(Call.FromArgs(Problem.Current, name, arg1, arg2, arg3, arg4, arg5)));
}
internal NonTightProblemException(Proposition offender) : base($"{offender} is inferrable from itself!")
{
Offender = offender;
}