public static void Main(string[] args)
{
if (args.Length < 2) {
Console.WriteLine("Usage: euler.exe axioms.n3 axioms... {questions.n3 | -sparql query.sparql}");
return;
}
// Load Axioms
bool sparql = false;
MemoryStore axioms = new MemoryStore();
for (int i = 0; i < args.Length-1; i++) {
if (i > 0 && i == args.Length-2 && args[i] == "-sparql") {
sparql = true;
break;
}
N3Reader axiomsreader = new N3Reader(args[i]);
axiomsreader.BaseUri = "http://www.example.org/arbitrary/base#";
axioms.Import(axiomsreader);
}
Euler engine = new Euler(axioms);
// Load question
if (!sparql) {
MemoryStore question = new MemoryStore();
question.Import(new N3Reader(args[args.Length-1]));
Proof[] proofs = engine.Prove(null, question.ToArray());
foreach (Proof p in proofs) {
Console.WriteLine(p.ToString());
}
} else {
using (StreamReader fs = new StreamReader(args[args.Length-1])) {
string q = fs.ReadToEnd();
Store store = new Store();
store.AddReasoner(engine);
SparqlEngine s = new SparqlEngine(q);
s.Run(store, Console.Out);
}
}
}
public static void Main()
{
// Create the instance data
MemoryStore dataModel = new MemoryStore();
BNode paris = new BNode("paris");
BNode orleans = new BNode("orleans");
BNode chartres = new BNode("chartres");
BNode amiens = new BNode("amiens");
BNode blois = new BNode("blois");
BNode bourges = new BNode("bourges");
BNode tours = new BNode("tours");
BNode lemans = new BNode("lemans");
BNode angers = new BNode("angers");
BNode nantes = new BNode("nantes");
Entity oneway = new Entity("http://www.agfa.com/w3c/euler/graph.axiom#oneway");
Entity path = new Entity("http://www.agfa.com/w3c/euler/graph.axiom#path");
dataModel.Add(new Statement(paris, oneway, orleans));
dataModel.Add(new Statement(paris, oneway, chartres));
dataModel.Add(new Statement(paris, oneway, amiens));
dataModel.Add(new Statement(orleans, oneway, blois));
dataModel.Add(new Statement(orleans, oneway, bourges));
dataModel.Add(new Statement(blois, oneway, tours));
dataModel.Add(new Statement(chartres, oneway, lemans));
dataModel.Add(new Statement(lemans, oneway, angers));
dataModel.Add(new Statement(lemans, oneway, tours));
dataModel.Add(new Statement(angers, oneway, nantes));
// Create the inference rules by reading them from a N3 string.
string rules =
"@prefix : <http://www.agfa.com/w3c/euler/graph.axiom#>.\n" +
"\n" +
"{ ?a :oneway ?b } => { ?a :path ?b } .\n" +
"{ ?a :path ?b . ?b :path ?c . } => { ?a :path ?c } .\n";
// Create our question in the form of a statement to test.
Statement question = new Statement(paris, path, nantes);
// Create the Euler engine
Euler engine = new Euler(new N3Reader(new StringReader(rules)));
// First Method of Inference:
// Ask the engine whether there is a path from paris to nantes.
// The Prove method will return a list of proofs, or an empty
// array if it could not find a proof.
foreach (Proof p in engine.Prove(dataModel, new Statement[] { question })) {
Console.WriteLine(p.ToString());
}
// Second Method of Inference:
// Apply the engine to the data model and then use the data
// model's Contains method to see if the statement is "in"
// the model + reasoning.
dataModel.AddReasoner(engine);
Console.WriteLine("Euler Says the Question is: " + dataModel.Contains(question));
}
private static void EulerQuery (SelectableSource source, string rules, Statement[] queries)
{
Store store = new Store (source);
Euler engine = new Euler(new N3Reader(new StringReader(rules)));
foreach (Proof p in engine.Prove (store, queries)) {
foreach (Statement s in p.Proved)
Console.WriteLine(s);
}
}