com.articulate.sigma.semRewrite.Clause Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of sigma-component Show documentation
Show all versions of sigma-component Show documentation
Sigma knowledge engineering system is an system for developing, viewing and debugging theories in first
order logic. It works with Knowledge Interchange Format (KIF) and is optimized for the Suggested Upper Merged
Ontology (SUMO) www.ontologyportal.org.
package com.articulate.sigma.semRewrite;
/*
Copyright 2014-2015 IPsoft
Author: Adam Pease [email protected]
In conjunctive normal form (CNF) a formula is a conjunct of
disjuncts. This is the list of disjuncts.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program ; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
*/
import java.util.*;
public class Clause {
public ArrayList disjuncts = new ArrayList();
/** *************************************************************
*/
public String toString() {
StringBuffer sb = new StringBuffer();
if (disjuncts.size() > 1)
sb.append("(");
for (int i = 0; i < disjuncts.size(); i++) {
Literal c = disjuncts.get(i);
sb.append(c.toString());
if (disjuncts.size() > 1 && i < disjuncts.size() - 1)
sb.append(" | ");
}
if (disjuncts.size() > 1)
sb.append(")");
return sb.toString();
}
/** *************************************************************
*/
public Clause deepCopy() {
Clause newd = new Clause();
for (int i = 0; i < disjuncts.size(); i++)
newd.disjuncts.add(disjuncts.get(i).deepCopy());
return newd;
}
/** ***************************************************************
*/
@Override
public boolean equals(Object o) {
if (!(o instanceof Clause))
return false;
Clause d = (Clause) o;
if (disjuncts.size() != d.disjuncts.size())
return false;
for (int i = 0; i < disjuncts.size(); i++)
if (!disjuncts.get(i).equals(d.disjuncts.get(i)))
return false;
return true;
}
/** ***************************************************************
*/
public boolean empty() {
if (disjuncts.size() == 0)
return true;
else
return false;
}
/** *************************************************************
*/
public void preProcessQuestionWords(List qwords) {
for (Literal c: disjuncts)
c.preProcessQuestionWords(qwords);
}
/** ***************************************************************
* Clear the bound flags on each Literal
*/
public void clearBound() {
for (int i = 0; i < disjuncts.size(); i++) {
Literal l = disjuncts.get(i);
if (l.bound)
l.bound = false;
}
}
/** ***************************************************************
* Clear the preserve flags on each Literal
*/
public void clearPreserve() {
for (int i = 0; i < disjuncts.size(); i++) {
Literal l = disjuncts.get(i);
if (l.preserve)
l.preserve = false;
}
}
/** ***************************************************************
* If literal is not marked "preserve" then remove it if bound and
* then reset the preserve flag. Note this should only be called
* on inputs, not rules.
*/
public void removeBound() {
//System.out.println("INFO in Disjunct.removeBound(): before " + this);
ArrayList newdis = new ArrayList();
for (int i = 0; i < disjuncts.size(); i++) {
Literal l = disjuncts.get(i);
if (!l.bound || l.preserve) {
l.bound = false;
l.preserve = false;
newdis.add(l);
}
}
disjuncts = newdis;
//System.out.println("INFO in Disjunct.removeBound(): after " + this);
}
/** ***************************************************************
* Copy bound flags to this set of clauses
*/
public void copyBoundFlags(Clause d) {
for (int i = 0; i < disjuncts.size(); i++) {
if (d.disjuncts.get(i).bound)
disjuncts.get(i).bound = true;
if (d.disjuncts.get(i).preserve)
disjuncts.get(i).preserve = true;
}
}
/** *************************************************************
* @return a clause that results from applying a binding list
* to this clause.
*/
public Clause applyBindings(HashMap bindings) {
Clause c = new Clause();
for (int i = 0; i < disjuncts.size(); i++) {
Literal l = disjuncts.get(i);
c.disjuncts.add(l.applyBindings(bindings));
}
return c;
}
/** *************************************************************
* The argument to this method is the rule and this is the sentence
* @return the set of variable bindings. The key is the variable
* and the value is the binding.
*/
public HashMap unify(Clause d) {
for (int i = 0; i < d.disjuncts.size(); i++) {
Literal c1 = d.disjuncts.get(i); // rule
//System.out.println("INFO in Disjunct.unify(): checking " + c1);
if (c1.pred.equals("isCELTclass") && c1.isGround())
if (Procedures.isCELTclass(c1).equals("true"))
return new HashMap();
if (c1.pred.equals("isSubclass") && c1.isGround())
if (Procedures.isSubclass(c1).equals("true"))
return new HashMap();
if (c1.pred.equals("isInstanceOf") && c1.isGround())
if (Procedures.isInstanceOf(c1).equals("true"))
return new HashMap();
if (c1.pred.equals("isSubAttribute") && c1.isGround())
if (Procedures.isSubAttribute(c1).equals("true")) {
return new HashMap();
}
for (int j = 0; j < disjuncts.size(); j++) {
Literal c2 = disjuncts.get(j);
HashMap bindings = c2.mguTermList(c1);
//System.out.println("INFO in Disjunct.unify(): checking " + c1 + " against " + c2);
if (bindings != null) {
if (c1.preserve)
c2.preserve = true;
c2.bound = true; // mark as bound in case the rule consumes the clauses ( a ==> rule not a ?=>)
//System.out.println("INFO in Disjunct.unify(): bound: " + c2);
return bindings;
}
}
}
//System.out.println("INFO in Disjunct.unify(): this: " + this);
//System.out.println("INFO in Disjunct.unify(): d: " + d);
return null;
}
}