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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
package rsacomb
import org.semanticweb.owlapi.model.{
OWLOntology,
OWLClass,
OWLSubObjectPropertyOfAxiom,
OWLSubClassOfAxiom,
OWLObjectProperty,
OWLObjectPropertyExpression,
OWLObjectSomeValuesFrom
}
import tech.oxfordsemantic.jrdfox.logic.{
IRI,
BodyFormula,
Atom,
Rule,
Term,
Variable
}
import scala.collection.JavaConverters._
import rsacomb.RSA._
object ProgramGenerator {
def apply(
ontology: OWLOntology,
term: Term
): RDFoxAxiomConverter =
new ProgramGenerator(ontology, term)
def generateRoleRules(
roles: Set[OWLObjectProperty]
): List[Rule] = {
def additional(pred: String): Seq[Rule] = {
val varX = Variable.create("X")
val varY = Variable.create("Y")
List(
Rule.create(
Atom.rdf(varX, IRI.create(pred), varY),
Atom.rdf(varX, IRI.create(pred ++ RSASuffix.Forward.getSuffix), varY)
),
Rule.create(
Atom.rdf(varX, IRI.create(pred), varY),
Atom.rdf(varX, IRI.create(pred ++ RSASuffix.Backward.getSuffix), varY)
),
Rule.create(
Atom.rdf(
varY,
IRI.create(pred ++ RSASuffix.Backward.getSuffix ++ "_inv"),
varX
),
Atom.rdf(varX, IRI.create(pred ++ RSASuffix.Forward.getSuffix), varY)
),
Rule.create(
Atom.rdf(
varY,
IRI.create(pred ++ RSASuffix.Forward.getSuffix ++ "_inv"),
varX
),
Atom.rdf(varX, IRI.create(pred ++ RSASuffix.Backward.getSuffix), varY)
)
)
}
roles
.map(_.getIRI.getIRIString)
.flatMap(additional)
.toList
}
def NIs(individuals: List[IRI]): List[Atom] =
individuals.map(Atom.rdf(_, IRI.RDF_TYPE, RSA.internal("NI")))
}
class ProgramGenerator(
ontology: OWLOntology,
term: Term
) extends RDFoxAxiomConverter(
term,
ontology.unsafeRoles,
SkolemStrategy.None,
RSASuffix.None
)
with RSAAxiom {
import RDFoxUtil._
def rules1(axiom: OWLSubClassOfAxiom): List[Rule] = {
val unfold = ontology.unfold(axiom).toList
// Fresh Variables
val v0 = IRI.create("v0_" ++ axiom.hashCode.toString)
val varX = Variable.create("X")
// Predicates
val atomA: Atom = {
val cls = axiom.getSubClass.asInstanceOf[OWLClass].getIRI
Atom.rdf(varX, IRI.RDF_TYPE, cls)
}
def notIn(t: Term): Atom = {
Atom.rdf(
t,
RSA.internal("notIn"),
RSA.internal(unfold.hashCode.toString)
)
}
val roleRf: Atom = {
val visitor =
new RDFoxPropertyExprConverter(varX, v0, RSASuffix.Forward)
axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getProperty
.accept(visitor)
.head
}
val atomB: Atom = {
val cls = axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getFiller
.asInstanceOf[OWLClass]
.getIRI
Atom.rdf(v0, IRI.RDF_TYPE, cls)
}
// TODO: To be consistent with the specifics of the visitor we are
// returning facts as `Rule`s with true body. While this is correct
// there is an easier way to import facts into RDFox. Are we able to
// do that?
val facts = unfold.map(x => Rule.create(notIn(x)))
val rules = List(
Rule.create(roleRf, atomA, notIn(varX)),
Rule.create(atomB, atomA, notIn(varX))
)
facts ++ rules
}
def rules2(axiom: OWLSubClassOfAxiom): List[Rule] = {
val roleR =
axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getProperty
if (ontology.confl(roleR) contains roleR) {
// Fresh Variables
val v0 = IRI.create("v0_" ++ axiom.hashCode.toString)
val v1 = IRI.create("v1_" ++ axiom.hashCode.toString)
val v2 = IRI.create("v2_" ++ axiom.hashCode.toString)
// Predicates
def atomA(t: Term): Atom = {
val cls = axiom.getSubClass.asInstanceOf[OWLClass].getIRI
Atom.rdf(t, IRI.RDF_TYPE, cls)
}
def roleRf(t1: Term, t2: Term): Atom = {
val visitor = new RDFoxPropertyExprConverter(t1, t2, RSASuffix.Forward)
roleR.accept(visitor).head
}
def atomB(t: Term): Atom = {
val cls = axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getFiller
.asInstanceOf[OWLClass]
.getIRI
Atom.rdf(t, IRI.RDF_TYPE, cls)
}
//Rules
List(
Rule.create(roleRf(v0, v1), atomA(v0)),
Rule.create(atomB(v1), atomA(v0)),
Rule.create(roleRf(v1, v2), atomA(v1)),
Rule.create(atomB(v2), atomA(v1))
)
} else {
List()
}
}
def rules3(axiom: OWLSubClassOfAxiom): List[Rule] = {
val cycle = ontology.cycle(axiom).toList
val roleR =
axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getProperty
// Fresh Variables
val v1 = IRI.create("v1_" ++ axiom.hashCode.toString)
// Predicates
def atomA(t: Term): Atom = {
val cls = axiom.getSubClass.asInstanceOf[OWLClass].getIRI
Atom.rdf(t, IRI.RDF_TYPE, cls)
}
def roleRf(t: Term): Atom = {
val visitor =
new RDFoxPropertyExprConverter(t, v1, RSASuffix.Forward)
roleR.accept(visitor).head
}
val atomB: Atom = {
val cls = axiom.getSuperClass
.asInstanceOf[OWLObjectSomeValuesFrom]
.getFiller
.asInstanceOf[OWLClass]
.getIRI
Atom.rdf(v1, IRI.RDF_TYPE, cls)
}
cycle.flatMap { x =>
List(
Rule.create(roleRf(x), atomA(x)),
Rule.create(atomB, atomA(x))
)
}
}
override def visit(axiom: OWLSubClassOfAxiom): List[Rule] = {
if (axiom.isT5) {
// TODO: get role in T5 axiom
// Assuming one role here
val role = axiom.objectPropertyExpressionsInSignature(0)
if (ontology.unsafeRoles.contains(role)) {
val visitor =
new RDFoxAxiomConverter(
term,
ontology.unsafeRoles,
SkolemStrategy.Standard(axiom.toString),
RSASuffix.Forward
)
axiom.accept(visitor)
} else {
rules1(axiom) ++ rules2(axiom) ++ rules3(axiom)
}
} else {
// Fallback to standard OWL to LP translation
super.visit(axiom)
}
}
override def visit(axiom: OWLSubObjectPropertyOfAxiom): List[Rule] = {
val varX = Variable.create("X")
val varY = Variable.create("Y")
val visitorF = new RDFoxAxiomConverter(
term,
ontology.unsafeRoles,
SkolemStrategy.None,
RSASuffix.Forward
)
val visitorB = new RDFoxAxiomConverter(
term,
ontology.unsafeRoles,
SkolemStrategy.None,
RSASuffix.Backward
)
axiom.accept(visitorB) ++ axiom.accept(visitorF)
}
}
|
