// Note: see -
// http://logic.stanford.edu/classes/cs157/2008/lectures/lecture15.pdf
// slide 12 for where this test example was taken from.
public static FOLKnowledgeBase createABCEqualityKnowledgeBase(
InferenceProcedure infp, bool includeEqualityAxioms)
{
FOLDomain domain = new FOLDomain();
domain.addConstant("A");
domain.addConstant("B");
domain.addConstant("C");
FOLKnowledgeBase kb = new FOLKnowledgeBase(domain, infp);
kb.tell("B = A");
kb.tell("B = C");
if (includeEqualityAxioms)
{
// Reflexivity Axiom
kb.tell("x = x");
// Symmetry Axiom
kb.tell("(x = y => y = x)");
// Transitivity Axiom
kb.tell("((x = y AND y = z) => x = z)");
}
return(kb);
}
private static void kingsDemo1(InferenceProcedure ip)
{
StandardizeApartIndexicalFactory.flush();
FOLKnowledgeBase kb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(ip);
String kbStr = kb.ToString();
List <Term> terms = new List <Term>();
terms.Add(new Constant("John"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kb.ask(query);
System.Console.WriteLine("Kings Knowledge Base:");
System.Console.WriteLine(kbStr);
System.Console.WriteLine("Query: " + query);
foreach (Proof p in answer.getProofs())
{
System.Console.Write(ProofPrinter.printProof(p));
System.Console.WriteLine("");
}
}
protected void testEqualityAndSubstitutionNoAxiomsKBabcdPDSucceeds(InferenceProcedure infp, bool expectedToFail)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory.createABCDEqualityAndSubstitutionKnowledgeBase(infp, false);
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Constant("D"));
Predicate query = new Predicate("P", terms);
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToFail)
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Size());
}
else
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Size());
Assert.IsTrue(0 == answer.getProofs().Get(0)
.getAnswerBindings().Size());
}
}
protected void testEqualityAndSubstitutionAxiomsKBabcdFFASucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory
.createABCDEqualityAndSubstitutionKnowledgeBase(infp, true);
List <Term> terms = new List <Term>();
terms.Add(new Constant("A"));
Function fa = new Function("F", terms);
terms = new List <Term>();
terms.Add(fa);
TermEquality query = new TermEquality(new Function("F", terms),
new Constant("A"));
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(0 == answer.getProofs()[0].getAnswerBindings()
.Count);
}
// Note: see -
// http://logic.stanford.edu/classes/cs157/2008/lectures/lecture15.pdf
// slide 16,17, and 18 for where this test example was taken from.
public static FOLKnowledgeBase createABCDEqualityAndSubstitutionKnowledgeBase(
InferenceProcedure infp, bool includeEqualityAxioms)
{
FOLDomain domain = new FOLDomain();
domain.addConstant("A");
domain.addConstant("B");
domain.addConstant("C");
domain.addConstant("D");
domain.addPredicate("P");
domain.addFunction("F");
FOLKnowledgeBase kb = new FOLKnowledgeBase(domain, infp);
kb.tell("F(A) = B");
kb.tell("F(B) = A");
kb.tell("C = D");
kb.tell("P(A)");
kb.tell("P(C)");
if (includeEqualityAxioms)
{
// Reflexivity Axiom
kb.tell("x = x");
// Symmetry Axiom
kb.tell("(x = y => y = x)");
// Transitivity Axiom
kb.tell("((x = y AND y = z) => x = z)");
// Function F Substitution Axiom
kb.tell("((x = y AND F(y) = z) => F(x) = z)");
// Predicate P Substitution Axiom
kb.tell("((x = y AND P(y)) => P(x))");
}
return(kb);
}
protected void testFullFOLKBLovesAnimalQueryNotKillsJackTunaSucceeds(
InferenceProcedure infp, bool expectedToTimeOut)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory
.createLovesAnimalKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Constant("Jack"));
terms.Add(new Constant("Tuna"));
NotSentence query = new NotSentence(new Predicate("Kills", terms));
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToTimeOut)
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsTrue(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
else
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(0 == answer.getProofs()[0]
.getAnswerBindings().Count);
}
}
public void setInferenceProcedure(InferenceProcedure inferenceProcedure)
{
if (null != inferenceProcedure)
{
this.inferenceProcedure = inferenceProcedure;
}
}
protected static void lovesAnimalDemo(InferenceProcedure ip)
{
StandardizeApartIndexicalFactory.flush();
FOLKnowledgeBase kb = FOLKnowledgeBaseFactory.createLovesAnimalKnowledgeBase(ip);
string kbStr = kb.ToString();
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Constant("Curiosity"));
terms.Add(new Constant("Tuna"));
Predicate query = new Predicate("Kills", terms);
InferenceResult answer = kb.ask(query);
System.Console.WriteLine("Loves Animal Knowledge Base:");
System.Console.WriteLine(kbStr);
System.Console.WriteLine("Query: " + query);
foreach (Proof p in answer.getProofs())
{
System.Console.Write(ProofPrinter.printProof(p));
System.Console.WriteLine("");
}
}
protected void testFullFOLKBLovesAnimalQueryKillsJackTunaFalse(InferenceProcedure infp, bool expectedToTimeOut)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory.createLovesAnimalKnowledgeBase(infp);
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Constant("Jack"));
terms.Add(new Constant("Tuna"));
Predicate query = new Predicate("Kills", terms);
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToTimeOut)
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsTrue(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Size());
}
else
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Size());
}
}
protected void testEqualityNoAxiomsKBabcAEqualsCSucceeds(InferenceProcedure infp, bool expectedToFail)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory.createABCEqualityKnowledgeBase(infp, false);
TermEquality query = new TermEquality(new Constant("A"), new Constant("C"));
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToFail)
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Size());
}
else
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Size());
Assert.IsTrue(0 == answer.getProofs().Get(0)
.getAnswerBindings().Size());
}
}
public static FOLKnowledgeBase createKingsKnowledgeBase(InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory.kingsDomain(), infp);
kb.tell("((King(x) AND Greedy(x)) => Evil(x))");
kb.tell("King(John)");
kb.tell("King(Richard)");
kb.tell("Greedy(John)");
return(kb);
}
public FOLKnowledgeBase(FOLDomain domain, InferenceProcedure inferenceProcedure, Unifier unifier)
{
this.parser = new FOLParser(new FOLDomain(domain));
this.inferenceProcedure = inferenceProcedure;
this.unifier = unifier;
//
this.substVisitor = new SubstVisitor();
this.variableCollector = new VariableCollector();
this._standardizeApart = new StandardizeApart(variableCollector, substVisitor);
this.cnfConverter = new CNFConverter(parser);
}
public static FOLKnowledgeBase createKingsKnowledgeBase(
InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory.kingsDomain(),
infp);
kb.tell("((King(x) AND Greedy(x)) => Evil(x))");
kb.tell("King(John)");
kb.tell("King(Richard)");
kb.tell("Greedy(John)");
return kb;
}
public static FOLKnowledgeBase createLovesAnimalKnowledgeBase(InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory.lovesAnimalDomain(), infp);
kb.tell("FORALL x (FORALL y (Animal(y) => Loves(x, y)) => EXISTS y Loves(y, x))");
kb.tell("FORALL x (EXISTS y (Animal(y) AND Kills(x, y)) => FORALL z NOT(Loves(z, x)))");
kb.tell("FORALL x (Animal(x) => Loves(Jack, x))");
kb.tell("(Kills(Jack, Tuna) OR Kills(Curiosity, Tuna))");
kb.tell("Cat(Tuna)");
kb.tell("FORALL x (Cat(x) => Animal(x))");
return(kb);
}
public FOLKnowledgeBase(FOLDomain domain,
InferenceProcedure inferenceProcedure, Unifier unifier)
{
this.parser = new FOLParser(new FOLDomain(domain));
this.inferenceProcedure = inferenceProcedure;
this.unifier = unifier;
//
this.substVisitor = new SubstVisitor();
this.variableCollector = new VariableCollector();
this._standardizeApart = new StandardizeApart(variableCollector,
substVisitor);
this.cnfConverter = new CNFConverter(parser);
}
public static FOLKnowledgeBase createWeaponsKnowledgeBase(InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory.weaponsDomain(), infp);
kb.tell("( (((American(x) AND Weapon(y)) AND Sells(x,y,z)) AND Hostile(z)) => Criminal(x))");
kb.tell(" Owns(Nono, M1)");
kb.tell(" Missile(M1)");
kb.tell("((Missile(x) AND Owns(Nono,x)) => Sells(West,x,Nono))");
kb.tell("(Missile(x) => Weapon(x))");
kb.tell("(Enemy(x,America) => Hostile(x))");
kb.tell("American(West)");
kb.tell("Enemy(Nono,America)");
return(kb);
}
protected void testDefiniteClauseKBKingsQueryRichardEvilFalse(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List<Term> terms = new List<Term>();
terms.Add(new Constant("Richard"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
protected void testDefiniteClauseKBKingsQueryRichardEvilFalse(InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory.createKingsKnowledgeBase(infp);
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Constant("Richard"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Size());
}
public static FOLKnowledgeBase createLovesAnimalKnowledgeBase(
InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory
.lovesAnimalDomain(), infp);
kb
.tell("FORALL x (FORALL y (Animal(y) => Loves(x, y)) => EXISTS y Loves(y, x))");
kb
.tell("FORALL x (EXISTS y (Animal(y) AND Kills(x, y)) => FORALL z NOT(Loves(z, x)))");
kb.tell("FORALL x (Animal(x) => Loves(Jack, x))");
kb.tell("(Kills(Jack, Tuna) OR Kills(Curiosity, Tuna))");
kb.tell("Cat(Tuna)");
kb.tell("FORALL x (Cat(x) => Animal(x))");
return kb;
}
public static FOLKnowledgeBase createWeaponsKnowledgeBase(
InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory
.weaponsDomain(), infp);
kb
.tell("( (((American(x) AND Weapon(y)) AND Sells(x,y,z)) AND Hostile(z)) => Criminal(x))");
kb.tell(" Owns(Nono, M1)");
kb.tell(" Missile(M1)");
kb.tell("((Missile(x) AND Owns(Nono,x)) => Sells(West,x,Nono))");
kb.tell("(Missile(x) => Weapon(x))");
kb.tell("(Enemy(x,America) => Hostile(x))");
kb.tell("American(West)");
kb.tell("Enemy(Nono,America)");
return kb;
}
protected void testDefiniteClauseKBKingsQueryEvilXReturnsJohnSucceeds(InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory.createKingsKnowledgeBase(infp);
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Size());
Assert.IsTrue(1 == answer.getProofs().Get(0).getAnswerBindings().Size());
Assert.AreEqual(new Constant("John"), answer.getProofs().Get(0).getAnswerBindings().Get(new Variable("x")));
}
//
// Protected Methods
//
protected void testDefiniteClauseKBKingsQueryCriminalXFalse(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Criminal", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
protected void testDefiniteClauseKBKingsQueryKingXReturnsJohnAndRichardSucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("King", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(2 == answer.getProofs().Count);
Assert.IsTrue(1 == answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.IsTrue(1 == answer.getProofs()[1].getAnswerBindings()
.Count);
bool gotJohn, gotRichard;
gotJohn = gotRichard = false;
Constant cJohn = new Constant("John");
Constant cRichard = new Constant("Richard");
foreach (Proof p in answer.getProofs())
{
Dictionary <Variable, Term> ans = p.getAnswerBindings();
Assert.AreEqual(1, ans.Count);
if (cJohn.Equals(ans[new Variable("x")]))
{
gotJohn = true;
}
if (cRichard.Equals(ans[new Variable("x")]))
{
gotRichard = true;
}
}
Assert.IsTrue(gotJohn);
Assert.IsTrue(gotRichard);
}
protected void testDefiniteClauseKBKingsQueryJohnEvilSucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Constant("John"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(0 == answer.getProofs()[0].getAnswerBindings()
.Count);
}
protected void testDefiniteClauseKBKingsQueryEvilXReturnsJohnSucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List<Term> terms = new List<Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Evil", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(1 == answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.AreEqual(new Constant("John"), answer.getProofs()[0]
.getAnswerBindings()[new Variable("x")]);
}
protected static void abcEqualityNoAxiomDemo(InferenceProcedure ip)
{
StandardizeApartIndexicalFactory.flush();
FOLKnowledgeBase kb = FOLKnowledgeBaseFactory.createABCEqualityKnowledgeBase(ip, false);
string kbStr = kb.ToString();
TermEquality query = new TermEquality(new Constant("A"), new Constant("C"));
InferenceResult answer = kb.ask(query);
System.Console.WriteLine("ABC Equality No Axiom Knowledge Base:");
System.Console.WriteLine(kbStr);
System.Console.WriteLine("Query: " + query);
foreach (Proof p in answer.getProofs())
{
System.Console.Write(ProofPrinter.printProof(p));
System.Console.WriteLine("");
}
}
public static FOLKnowledgeBase createRingOfThievesKnowledgeBase(
InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory
.ringOfThievesDomain(), infp);
// s(x) => ~c(x) One who skis never gets caught
kb.tell("(Skis(x) => NOT(Caught(x)))");
// c(x) => ~s(x) Those who are caught don't ever ski
kb.tell("(Caught(x) => NOT(Skis(x)))");
// p(x,y) & c(y) => s(x) Jailbird parents have skiing kids
kb.tell("((Parent(x,y) AND Caught(y)) => Skis(x))");
// s(x) & f(x,y) => s(y) All friends ski together
kb.tell("(Skis(x) AND Friend(x,y) => Skis(y))");
// f(x,y) => f(y,x) Friendship is symmetric
kb.tell("(Friend(x,y) => Friend(y,x))");
// FACTS
// 1. { p(Mike,Joe) } Premise
kb.tell("Parent(Mike, Joe)");
// 2. { p(Janet,Joe) } Premise
kb.tell("Parent(Janet,Joe)");
// 3. { p(Nancy,Mike) } Premise
kb.tell("Parent(Nancy,Mike)");
// 4. { p(Ernie,Janet) } Premise
kb.tell("Parent(Ernie,Janet)");
// 5. { p(Bert,Nancy) } Premise
kb.tell("Parent(Bert,Nancy)");
// 6. { p(Red,Ernie) } Premise
kb.tell("Parent(Red,Ernie)");
// 7. { f(Red,Bert) } Premise
kb.tell("Friend(Red,Bert)");
// 8. { f(Drew,Nancy) } Premise
kb.tell("Friend(Drew,Nancy)");
// 9. { c(Mike) } Premise
kb.tell("Caught(Mike)");
// 10. { c(Ernie) } Premise
kb.tell("Caught(Ernie)");
return kb;
}
protected void testHornClauseKBRingOfThievesQuerySkisXReturnsNancyRedBertDrew(
InferenceProcedure infp)
{
FOLKnowledgeBase rotkb = FOLKnowledgeBaseFactory
.createRingOfThievesKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Skis", terms);
InferenceResult answer = rotkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
// DB can expand infinitely so is only partial.
Assert.IsTrue(answer.isPartialResultDueToTimeout());
Assert.AreEqual(4, answer.getProofs().Count);
Assert.AreEqual(1, answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[1].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[2].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[3].getAnswerBindings()
.Count);
List <Constant> expected = new List <Constant>();
expected.Add(new Constant("Nancy"));
expected.Add(new Constant("Red"));
expected.Add(new Constant("Bert"));
expected.Add(new Constant("Drew"));
foreach (Proof p in answer.getProofs())
{
expected.Remove((Constant)p.getAnswerBindings()[new Variable("x")]);
}
Assert.AreEqual(0, expected.Count);
}
public static FOLKnowledgeBase createRingOfThievesKnowledgeBase(
InferenceProcedure infp)
{
FOLKnowledgeBase kb = new FOLKnowledgeBase(DomainFactory
.ringOfThievesDomain(), infp);
// s(x) => ~c(x) One who skis never gets caught
kb.tell("(Skis(x) => NOT(Caught(x)))");
// c(x) => ~s(x) Those who are caught don't ever ski
kb.tell("(Caught(x) => NOT(Skis(x)))");
// p(x,y) & c(y) => s(x) Jailbird parents have skiing kids
kb.tell("((Parent(x,y) AND Caught(y)) => Skis(x))");
// s(x) & f(x,y) => s(y) All friends ski together
kb.tell("(Skis(x) AND Friend(x,y) => Skis(y))");
// f(x,y) => f(y,x) Friendship is symmetric
kb.tell("(Friend(x,y) => Friend(y,x))");
// FACTS
// 1. { p(Mike,Joe) } Premise
kb.tell("Parent(Mike, Joe)");
// 2. { p(Janet,Joe) } Premise
kb.tell("Parent(Janet,Joe)");
// 3. { p(Nancy,Mike) } Premise
kb.tell("Parent(Nancy,Mike)");
// 4. { p(Ernie,Janet) } Premise
kb.tell("Parent(Ernie,Janet)");
// 5. { p(Bert,Nancy) } Premise
kb.tell("Parent(Bert,Nancy)");
// 6. { p(Red,Ernie) } Premise
kb.tell("Parent(Red,Ernie)");
// 7. { f(Red,Bert) } Premise
kb.tell("Friend(Red,Bert)");
// 8. { f(Drew,Nancy) } Premise
kb.tell("Friend(Drew,Nancy)");
// 9. { c(Mike) } Premise
kb.tell("Caught(Mike)");
// 10. { c(Ernie) } Premise
kb.tell("Caught(Ernie)");
return(kb);
}
protected void testDefiniteClauseKBWeaponsQueryCriminalXReturnsWestSucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase wkb = FOLKnowledgeBaseFactory
.createWeaponsKnowledgeBase(infp);
List <Term> terms = new List <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Criminal", terms);
InferenceResult answer = wkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(1 == answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.AreEqual(new Constant("West"), answer.getProofs()[0]
.getAnswerBindings()[new Variable("x")]);
}
protected static void weaponsDemo(InferenceProcedure ip)
{
StandardizeApartIndexicalFactory.flush();
FOLKnowledgeBase kb = FOLKnowledgeBaseFactory.createWeaponsKnowledgeBase(ip);
string kbStr = kb.ToString();
ICollection <Term> terms = CollectionFactory.CreateQueue <Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Criminal", terms);
InferenceResult answer = kb.ask(query);
System.Console.WriteLine("Weapons Knowledge Base:");
System.Console.WriteLine(kbStr);
System.Console.WriteLine("Query: " + query);
foreach (Proof p in answer.getProofs())
{
System.Console.Write(ProofPrinter.printProof(p));
System.Console.WriteLine("");
}
}
public FOLKnowledgeBase(FOLDomain domain,
InferenceProcedure inferenceProcedure) : this(domain, inferenceProcedure, new Unifier())
{
}
public void setInferenceProcedure(InferenceProcedure inferenceProcedure)
{
if (null != inferenceProcedure)
{
this.inferenceProcedure = inferenceProcedure;
}
}
public FOLKnowledgeBase(FOLDomain domain, InferenceProcedure inferenceProcedure)
: this(domain, inferenceProcedure, new Unifier())
{
}
protected void testFullFOLKBLovesAnimalQueryKillsJackTunaFalse(
InferenceProcedure infp, bool expectedToTimeOut)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory
.createLovesAnimalKnowledgeBase(infp);
List<Term> terms = new List<Term>();
terms.Add(new Constant("Jack"));
terms.Add(new Constant("Tuna"));
Predicate query = new Predicate("Kills", terms);
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToTimeOut)
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsTrue(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
else
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
}
// Note: see -
// http://logic.stanford.edu/classes/cs157/2008/lectures/lecture15.pdf
// slide 12 for where this test example was taken from.
public static FOLKnowledgeBase createABCEqualityKnowledgeBase(
InferenceProcedure infp, bool includeEqualityAxioms)
{
FOLDomain domain = new FOLDomain();
domain.addConstant("A");
domain.addConstant("B");
domain.addConstant("C");
FOLKnowledgeBase kb = new FOLKnowledgeBase(domain, infp);
kb.tell("B = A");
kb.tell("B = C");
if (includeEqualityAxioms)
{
// Reflexivity Axiom
kb.tell("x = x");
// Symmetry Axiom
kb.tell("(x = y => y = x)");
// Transitivity Axiom
kb.tell("((x = y AND y = z) => x = z)");
}
return kb;
}
// Note: see -
// http://logic.stanford.edu/classes/cs157/2008/lectures/lecture15.pdf
// slide 16,17, and 18 for where this test example was taken from.
public static FOLKnowledgeBase createABCDEqualityAndSubstitutionKnowledgeBase(
InferenceProcedure infp, bool includeEqualityAxioms)
{
FOLDomain domain = new FOLDomain();
domain.addConstant("A");
domain.addConstant("B");
domain.addConstant("C");
domain.addConstant("D");
domain.addPredicate("P");
domain.addFunction("F");
FOLKnowledgeBase kb = new FOLKnowledgeBase(domain, infp);
kb.tell("F(A) = B");
kb.tell("F(B) = A");
kb.tell("C = D");
kb.tell("P(A)");
kb.tell("P(C)");
if (includeEqualityAxioms)
{
// Reflexivity Axiom
kb.tell("x = x");
// Symmetry Axiom
kb.tell("(x = y => y = x)");
// Transitivity Axiom
kb.tell("((x = y AND y = z) => x = z)");
// Function F Substitution Axiom
kb.tell("((x = y AND F(y) = z) => F(x) = z)");
// Predicate P Substitution Axiom
kb.tell("((x = y AND P(y)) => P(x))");
}
return kb;
}
protected void testEqualityNoAxiomsKBabcAEqualsCSucceeds(
InferenceProcedure infp, bool expectedToFail)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory
.createABCEqualityKnowledgeBase(infp, false);
TermEquality query = new TermEquality(new Constant("A"), new Constant(
"C"));
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToFail)
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
else
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(0 == answer.getProofs()[0]
.getAnswerBindings().Count);
}
}
protected void testHornClauseKBRingOfThievesQuerySkisXReturnsNancyRedBertDrew(
InferenceProcedure infp)
{
FOLKnowledgeBase rotkb = FOLKnowledgeBaseFactory
.createRingOfThievesKnowledgeBase(infp);
List<Term> terms = new List<Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("Skis", terms);
InferenceResult answer = rotkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
// DB can expand infinitely so is only partial.
Assert.IsTrue(answer.isPartialResultDueToTimeout());
Assert.AreEqual(4, answer.getProofs().Count);
Assert.AreEqual(1, answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[1].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[2].getAnswerBindings()
.Count);
Assert.AreEqual(1, answer.getProofs()[3].getAnswerBindings()
.Count);
List<Constant> expected = new List<Constant>();
expected.Add(new Constant("Nancy"));
expected.Add(new Constant("Red"));
expected.Add(new Constant("Bert"));
expected.Add(new Constant("Drew"));
foreach (Proof p in answer.getProofs())
{
expected.Remove((Constant)p.getAnswerBindings()[new Variable("x")]);
}
Assert.AreEqual(0, expected.Count);
}
protected void testEqualityAndSubstitutionNoAxiomsKBabcdPFFASucceeds(
InferenceProcedure infp, bool expectedToFail)
{
FOLKnowledgeBase akb = FOLKnowledgeBaseFactory
.createABCDEqualityAndSubstitutionKnowledgeBase(infp, false);
List<Term> terms = new List<Term>();
terms.Add(new Constant("A"));
Function fa = new Function("F", terms);
terms = new List<Term>();
terms.Add(fa);
Function ffa = new Function("F", terms);
terms = new List<Term>();
terms.Add(ffa);
Predicate query = new Predicate("P", terms);
InferenceResult answer = akb.ask(query);
Assert.IsTrue(null != answer);
if (expectedToFail)
{
Assert.IsTrue(answer.isPossiblyFalse());
Assert.IsFalse(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(0 == answer.getProofs().Count);
}
else
{
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(1 == answer.getProofs().Count);
Assert.IsTrue(0 == answer.getProofs()[0]
.getAnswerBindings().Count);
}
}
protected void testDefiniteClauseKBKingsQueryKingXReturnsJohnAndRichardSucceeds(
InferenceProcedure infp)
{
FOLKnowledgeBase kkb = FOLKnowledgeBaseFactory
.createKingsKnowledgeBase(infp);
List<Term> terms = new List<Term>();
terms.Add(new Variable("x"));
Predicate query = new Predicate("King", terms);
InferenceResult answer = kkb.ask(query);
Assert.IsTrue(null != answer);
Assert.IsFalse(answer.isPossiblyFalse());
Assert.IsTrue(answer.isTrue());
Assert.IsFalse(answer.isUnknownDueToTimeout());
Assert.IsFalse(answer.isPartialResultDueToTimeout());
Assert.IsTrue(2 == answer.getProofs().Count);
Assert.IsTrue(1 == answer.getProofs()[0].getAnswerBindings()
.Count);
Assert.IsTrue(1 == answer.getProofs()[1].getAnswerBindings()
.Count);
bool gotJohn, gotRichard;
gotJohn = gotRichard = false;
Constant cJohn = new Constant("John");
Constant cRichard = new Constant("Richard");
foreach (Proof p in answer.getProofs())
{
Dictionary<Variable, Term> ans = p.getAnswerBindings();
Assert.AreEqual(1, ans.Count);
if (cJohn.Equals(ans[new Variable("x")]))
{
gotJohn = true;
}
if (cRichard.Equals(ans[new Variable("x")]))
{
gotRichard = true;
}
}
Assert.IsTrue(gotJohn);
Assert.IsTrue(gotRichard);
}