// Lifted multiplication operation
public LiftedSet <γ, Cp> Mult(LiftedSet <γ, Cp> a, LiftedSet <γ, Cp> b)
{
List <γ> coefficients = new List <γ>();
// Sanity check to make sure we have the right number of coefficients
Debug.Assert(a.coefficients.Count() == _p.Symbols().Count);
Debug.Assert(b.coefficients.Count() == _p.Symbols().Count);
foreach (var operandIndices in _multMap)
{
γ k = _semiring.AdditiveIdentity;
foreach (var tuple in operandIndices)
{
var i = tuple.Item1;
var j = tuple.Item2;
var combined = _semiring.Mult(a.coefficients.ElementAt(i),
b.coefficients.ElementAt(j));
// This Add combines two values to one using the underlying semiring
k = _semiring.Add(k, combined);
}
// This is List.Add tacking the next coefficient onto the end of the list
coefficients.Add(k);
}
return(new LiftedSet <γ, Cp> {
coefficients = coefficients
});
}
public LiftedSet <γ, Cp> Prepare(T element)
{
var prepped = _hPredicate.Prepare(element);
int index = _hPredicate.Symbols().IndexOf(prepped);
// Build a "one-hot" vector with a single coefficient set
IList <γ> coefficients = _hPredicate.Symbols()
.Select(x => _underlying.Semiring.AdditiveIdentity)
.ToList();
coefficients[index] = _underlying.Prepare(element);
return(new LiftedSet <γ, Cp>
{
coefficients = coefficients
});
}
public LiftedSemiring(ISemiring <γ> semiring, HPredicate <Cp, T> p, List <List <Tuple <int, int> > > multMap)
{
// Sanity check to make sure there's an entry in the multiplication map for
// each element of the predicate's state set
if (multMap.Count != p.Symbols().Count)
{
throw new System.Exception(string.Format("Assert failed, multMap.Count = {0} p.Symbols().Count = {1}",
multMap.Count,
p.Symbols().Count));
}
Debug.Assert(multMap.Count == p.Symbols().Count);
_semiring = semiring;
_p = p;
_multMap = multMap;
}