aima.logic.fol
Class Unifier

java.lang.Object
  aima.logic.fol.Unifier

public class Unifier
extends java.lang.Object

Constructor Summary

Unifier()

Method Summary

protected boolean	occurCheck(java.util.Map<Variable,Term> theta, Variable var, FOLNode x)
java.util.Map<Variable,Term>	unify(FOLNode x, FOLNode y)
java.util.Map<Variable,Term>	unify(FOLNode x, FOLNode y, java.util.Map<Variable,Term> theta) function UNIFY(x, y, theta) returns a substitution to make x and y identical inputs: x, a variable, constant, list, or compound y, a variable, constant, list, or compound theta, the substitution built up so far (optional, defaults to empty)
java.util.Map<Variable,Term>	unify(java.util.List<? extends FOLNode> x, java.util.List<? extends FOLNode> y, java.util.Map<Variable,Term> theta)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Unifier

public Unifier()

Method Detail

unify

public java.util.Map<Variable,Term> unify(FOLNode x,
                                          FOLNode y)

unify

public java.util.Map<Variable,Term> unify(FOLNode x,
                                          FOLNode y,
                                          java.util.Map<Variable,Term> theta)

function UNIFY(x, y, theta) returns a substitution to make x and y identical inputs: x, a variable, constant, list, or compound y, a variable, constant, list, or compound theta, the substitution built up so far (optional, defaults to empty)

Returns:

a Map representing the substitution (i.e. a set of variable/term pairs, see pg. 254 for a description) or null which is used to indicate a failure to unify.

unify

public java.util.Map<Variable,Term> unify(java.util.List<? extends FOLNode> x,
                                          java.util.List<? extends FOLNode> y,
                                          java.util.Map<Variable,Term> theta)

occurCheck

protected boolean occurCheck(java.util.Map<Variable,Term> theta,
                             Variable var,
                             FOLNode x)