private static void AddFluentClauses(Problem problem, bool requireActivationSupport, bool requireDeactivationSupport,
FluentInstantiation before, FluentInstantiation after)
{
var activate = Activate(before);
if (requireActivationSupport)
{
activate.RequireHaveSupport();
}
var deactivate = Deactivate(before);
if (requireDeactivationSupport)
{
deactivate.RequireHaveSupport();
}
// TODO - optimize these to generate signed indices directly; this will reduce garbage
// activate => after
problem.AddClause(after, Not(activate));
// deactivate => not after
problem.AddClause(Not(after), Not(deactivate));
// before => after | deactivate
problem.AddClause(Not(before), after, deactivate);
// not before => not after | activate
problem.AddClause(before, Not(after), activate);
// Can't simultaneously activate and deactivate
problem.AddClause(0, 1, activate, deactivate);
}
/// <summary>
/// Add clauses that follow from user-defined bounds, e.g. from transitivity.
/// </summary>
/// <returns></returns>
public override string Preprocess()
{
void PreprecessBounds(List <ConstantBound> constraints, int sign)
{
foreach (var p in Propositions)
{
p.Validate();
}
constraints.Sort((a, b) => sign * Comparer.Default.Compare(a.Bound, b.Bound));
// Add forward inferences: if v < bounds[i], then v < bounds[i+1]
for (int i = 0; i < constraints.Count - 1; i++)
{
var stronger = constraints[i];
var weaker = constraints[i + 1];
Problem.AddClause(Language.Not(stronger), weaker);
}
}
foreach (var v in Variables)
{
PreprecessBounds(v.UpperConstantBounds, 1);
PreprecessBounds(v.LowerConstantBounds, -1);
// Make sure there aren't any propositions dependent on the truth of functional constraint.
// We *could* allow this, but given that functional constraint have measure zero, the only
// way it's possible for them to be unsatisfied with non-zero probability is through
// floating-point quantization. That suggests that someone trying to make a proposition
// dependent on a != b+C is probably making a mistake.
if (v.AllFunctionalConstraints != null)
{
foreach (var f in v.AllFunctionalConstraints)
{
if (f.IsDependency)
{
throw new InvalidOperationException($"{f.Name}: Inferences dependent on the truth of functional constraint are not supported.");
}
}
}
}
return(null);
}