/**
* Conditional deduction or induction, with variable unification
*
* @param conditional The premise that is an Implication with a Conjunction as condition
* @param index The location of the shared term in the condition
* @param statement The second premise that is a statement
* @param side The location of the shared term in the statement
* @param memory Reference to the memory
*/
private static void conditionalDedIndWithVar(
Implication conditional, short index, Statement statement, short side, Memory memory) {
CompoundTerm condition = (CompoundTerm) conditional.getSubject();
Term component = condition.componentAt(index);
Term component2 = null;
if (statement instanceof Inheritance) {
component2 = statement;
side = -1;
} else if (statement instanceof Implication) {
component2 = statement.componentAt(side);
}
if ((component2 != null)
&& Variable.unify(Symbols.VAR_INDEPENDENT, component, component2, conditional, statement)) {
SyllogisticRules.conditionalDedInd(conditional, index, statement, side, memory);
}
}
/**
* Entry point of the inference engine
*
* @param tLink The selected TaskLink, which will provide a task
* @param bLink The selected TermLink, which may provide a belief
* @param memory Reference to the memory
*/
public static void reason(TaskLink tLink, TermLink bLink, Memory memory) {
Task task = memory.currentTask;
Sentence taskSentence = task.getSentence();
Term taskTerm = (Term) taskSentence.getContent().clone(); // cloning for substitution
Term beliefTerm = (Term) bLink.getTarget().clone(); // cloning for substitution
Concept beliefConcept = memory.termToConcept(beliefTerm);
Sentence belief = null;
if (beliefConcept != null) {
belief = beliefConcept.getBelief(task);
}
memory.currentBelief = belief; // may be null
if (belief != null) {
LocalRules.match(task, belief, memory);
}
if (!memory.noResult()) {
return;
}
short tIndex = tLink.getIndex(0);
short bIndex = bLink.getIndex(0);
switch (tLink.getType()) { // dispatch first by TaskLink type
case TermLink.SELF:
switch (bLink.getType()) {
case TermLink.COMPONENT:
compoundAndSelf((CompoundTerm) taskTerm, beliefTerm, true, memory);
break;
case TermLink.COMPOUND:
compoundAndSelf((CompoundTerm) beliefTerm, taskTerm, false, memory);
break;
case TermLink.COMPONENT_STATEMENT:
if (belief != null) {
SyllogisticRules.detachment(task.getSentence(), belief, bIndex, memory);
}
break;
case TermLink.COMPOUND_STATEMENT:
if (belief != null) {
SyllogisticRules.detachment(belief, task.getSentence(), bIndex, memory);
}
break;
case TermLink.COMPONENT_CONDITION:
if (belief != null) {
bIndex = bLink.getIndex(1);
SyllogisticRules.conditionalDedInd(
(Implication) taskTerm, bIndex, beliefTerm, tIndex, memory);
}
break;
case TermLink.COMPOUND_CONDITION:
if (belief != null) {
bIndex = bLink.getIndex(1);
SyllogisticRules.conditionalDedInd(
(Implication) beliefTerm, bIndex, taskTerm, tIndex, memory);
}
break;
}
break;
case TermLink.COMPOUND:
switch (bLink.getType()) {
case TermLink.COMPOUND:
compoundAndCompound((CompoundTerm) taskTerm, (CompoundTerm) beliefTerm, memory);
break;
case TermLink.COMPOUND_STATEMENT:
compoundAndStatement(
(CompoundTerm) taskTerm,
tIndex,
(Statement) beliefTerm,
bIndex,
beliefTerm,
memory);
break;
case TermLink.COMPOUND_CONDITION:
if (belief != null) {
if (beliefTerm instanceof Implication) {
SyllogisticRules.conditionalDedInd(
(Implication) beliefTerm, bIndex, taskTerm, -1, memory);
} else if (beliefTerm instanceof Equivalence) {
SyllogisticRules.conditionalAna(
(Equivalence) beliefTerm, bIndex, taskTerm, -1, memory);
}
}
break;
}
break;
case TermLink.COMPOUND_STATEMENT:
switch (bLink.getType()) {
case TermLink.COMPONENT:
componentAndStatement(
(CompoundTerm) memory.currentTerm, bIndex, (Statement) taskTerm, tIndex, memory);
break;
case TermLink.COMPOUND:
compoundAndStatement(
(CompoundTerm) beliefTerm,
bIndex,
(Statement) taskTerm,
tIndex,
beliefTerm,
memory);
break;
case TermLink.COMPOUND_STATEMENT:
if (belief != null) {
// bIndex = bLink.getIndex(1);
syllogisms(tLink, bLink, taskTerm, beliefTerm, memory);
}
break;
case TermLink.COMPOUND_CONDITION:
if (belief != null) {
bIndex = bLink.getIndex(1);
if (beliefTerm instanceof Implication) {
conditionalDedIndWithVar(
(Implication) beliefTerm, bIndex, (Statement) taskTerm, tIndex, memory);
}
}
break;
}
break;
case TermLink.COMPOUND_CONDITION:
switch (bLink.getType()) {
case TermLink.COMPOUND_STATEMENT:
if (belief != null) {
// if (beliefTerm instanceof Implication)
// TODO adding instanceof test changes results of Example-NAL6-in.txt
// TODO maybe put instanceof test within conditionalDedIndWithVar()
conditionalDedIndWithVar(
(Implication) taskTerm, tIndex, (Statement) beliefTerm, bIndex, memory);
}
break;
}
break;
}
}