/**
* C ⊓ D' ⊑ E → {D' ⊑ A, C ⊓ A ⊑ E}
*
* @param gcis
* @return
*/
boolean rule2(final IFactory factory, final Inclusion[] gcis) {
boolean result = false;
if (lhs instanceof Conjunction) {
Conjunction conjunction = (Conjunction) lhs;
final AbstractConcept[] concepts = conjunction.getConcepts();
if (concepts.length == 1) {
// unwrap redundant conjuncts
gcis[0] = new GCI(concepts[0], rhs);
result = true;
} else if (concepts.length == 0) {
log.warn("Empty conjunct detected in: " + this);
gcis[0] = new GCI(IFactory.TOP_CONCEPT, rhs);
result = true;
} else {
// Swap out any non-Concept concepts (ie Existentials)
for (int i = 0; !result && i < concepts.length; i++) {
if (!(concepts[i] instanceof Concept)) {
final Concept a = getA(factory, concepts[i]);
gcis[0] = new GCI(concepts[i], a);
final AbstractConcept[] newConcepts = new AbstractConcept[concepts.length];
System.arraycopy(concepts, 0, newConcepts, 0, concepts.length);
newConcepts[i] = a;
gcis[1] = new GCI(new Conjunction(newConcepts), rhs);
result = true;
}
}
if (!result) {
if (concepts.length > 2) {
// Binarise a conjunction of Concepts (expected/assumed
// by NF1)
result = true;
final AbstractConcept[] newConcepts = new AbstractConcept[concepts.length - 1];
System.arraycopy(concepts, 1, newConcepts, 0, concepts.length - 1);
final AbstractConcept d = new Conjunction(newConcepts);
final Concept a = getA(factory, d);
final AbstractConcept cAndA = new Conjunction(new AbstractConcept[] {concepts[0], a});
gcis[0] = new GCI(cAndA, rhs);
gcis[1] = new GCI(d, a);
} else if (concepts.length < 2) {
throw new AssertionError(
"Conjunctions of fewer than "
+ "two elements should not exist at this point: "
+ this);
}
}
}
}
return result;
}
@Override
public NormalFormGCI getNormalForm() {
final NormalFormGCI result;
// try {
if (lhs instanceof Concept) {
if (rhs instanceof Concept) {
final int newLhs = lhs.hashCode();
result = NF1a.getInstance(newLhs, rhs.hashCode());
} else if (rhs instanceof Existential) {
final Existential existential = (Existential) rhs;
result =
NF2.getInstance(
lhs.hashCode(), existential.getRole(), existential.getConcept().hashCode());
} else if (rhs instanceof Datatype) {
final Datatype datatype = (Datatype) rhs;
result = NF7.getInstance(lhs.hashCode(), datatype);
} else {
throw new IllegalStateException(
"GCI is not in Normal Form: "
+ "lhs is Concept but rhs is neither Concept, "
+ "Existential nor Datatype; it is "
+ rhs);
}
} else if (lhs instanceof Conjunction) {
final Conjunction conjunction = (Conjunction) lhs;
final AbstractConcept[] concepts = conjunction.getConcepts();
if (concepts.length == 1) {
result = NF1a.getInstance(concepts[0].hashCode(), rhs.hashCode());
} else if (concepts.length == 2) {
result = NF1b.getInstance(concepts[0].hashCode(), concepts[1].hashCode(), rhs.hashCode());
} else {
throw new IllegalStateException(
"Conjunction should have exactly one or two "
+ "Concepts not "
+ concepts.length
+ ": "
+ conjunction);
}
} else if (lhs instanceof Existential) {
Existential existential = (Existential) lhs;
result =
NF3.getInstance(
existential.getRole(), existential.getConcept().hashCode(), rhs.hashCode());
} else if (lhs instanceof Datatype) {
Datatype datatype = (Datatype) lhs;
result = NF8.getInstance(datatype, rhs.hashCode());
} else {
throw new IllegalStateException("GCI is not in Normal Form: " + lhs + ", " + rhs);
}
return result;
}
/**
* B ⊑ C ⊓ D → {B ⊑ C, B ⊑ D}
*
* @param gcis
* @return
*/
Inclusion[] rule7(Inclusion[] gcis) {
assert isRule7Applicable();
final Conjunction conjunction = (Conjunction) rhs;
final AbstractConcept[] concepts = conjunction.getConcepts();
if (concepts.length > gcis.length) {
gcis = new Inclusion[concepts.length];
}
for (int i = 0; i < concepts.length; i++) {
gcis[i] = new GCI(lhs, concepts[i]);
}
return gcis;
}
