1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
// This example demonstrates general reasoning with
// the Euler engine based on Jos De Roo's Euler proof
// mechanism. The example is based on the "graph"
// example from Euler.
using System;
using System.IO;
using SemWeb;
using SemWeb.Inference;
public class EulerTest {
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));
}
}
|
