private void recursiveFetch(Dictionary<Variable, Term> theta, Literal l,
List<Literal> remainingLiterals,
List<Dictionary<Variable, Term>> possibleSubstitutions)
{
// Find all substitutions for current predicate based on the
// substitutions of prior predicates in the list (i.e. SUBST with
// theta).
List<Dictionary<Variable, Term>> pSubsts = fetch(subst(theta, l));
// No substitutions, therefore cannot continue
if (null == pSubsts)
{
return;
}
foreach (Dictionary<Variable, Term> psubst in pSubsts)
{
// Ensure all prior substitution information is maintained
// along the chain of predicates (i.e. for shared variables
// across the predicates).
foreach(Variable key in theta.Keys)
{
psubst.Add(key,theta[key]);
}
if (remainingLiterals.Count == 0)
{
// This means I am at the end of the chain of predicates
// and have found a valid substitution.
possibleSubstitutions.Add(psubst);
}
else
{
// Need to move to the next link in the chain of substitutions
Literal first = remainingLiterals[0];
List<Literal> rest = remainingLiterals.Skip(1).ToList<Literal>();
recursiveFetch(psubst, first, rest, possibleSubstitutions);
}
}
}
