model

Class Arithmetic

java.lang.Object

model.Arithmetic

All Implemented Interfaces:

Clause, PCExpression

public class Arithmetic
extends Object
implements Clause

This class represents arithmetic expressions. It is a binary operator. It extends Clause.

Arithmetic expressions are only comparisons between numbers. Their operands must be bound before evaluation.

Author:

Alexandre Camus

Field Summary

Fields

Modifier and Type	Field and Description
private Unifiable	operand1
private Unifiable	operand2
private String	symbol

Constructor Summary

Constructors

Constructor and Description
Arithmetic(Unifiable operand1, String symbol, Unifiable operand2) Constructor of the class

Method Summary

Methods

Modifier and Type	Method and Description
Unifiable	getOperand1() Gets the left operand of the arithmetic expression.
Unifiable	getOperand2() Gets the right operand of the arithmetic expression.
ArithmeticSolutionNode	getSolver(RuleSet rules, SubstitutionSet parentSolution, AbstractSolutionNode parentNode) Creates a solver which is a node in the tree proof.
String	getSymbol() Gets the symbol of the arithmetic expression.
Arithmetic	replaceVariables(SubstitutionSet s) Replaces all the variables in the arithmetic expression according to the specified bindings.
Arithmetic	standardizeVariablesApart(Hashtable<Variable,Variable> newVars) Standardizes the variables in order to be sure that there won't be any variable clashes.
String	toString() Returns the arithmetic expression under the form of: "operand1 'symbol' operand2".

Methods inherited from class java.lang.Object

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

Field Detail

operand1

private Unifiable operand1

operand2

private Unifiable operand2

symbol

private String symbol

Constructor Detail

Arithmetic

public Arithmetic(Unifiable operand1,
          String symbol,
          Unifiable operand2)

Constructor of the class

Parameters:

operand1 - the left operand of the arithmetic expression.

symbol - the symbol of the arithmetic expression.

operand2 - the right operand of the arithmetic expression.

Method Detail

getOperand1

public Unifiable getOperand1()

Gets the left operand of the arithmetic expression.

Returns:

the left operand of the arithmetic expression.

getOperand2

public Unifiable getOperand2()

Gets the right operand of the arithmetic expression.

Returns:

the right operand of the arithmetic expression.

getSymbol

public String getSymbol()

Gets the symbol of the arithmetic expression.

Returns:

the symbol of the arithmetic expression.

getSolver

public ArithmeticSolutionNode getSolver(RuleSet rules,
                               SubstitutionSet parentSolution,
                               AbstractSolutionNode parentNode)

Creates a solver which is a node in the tree proof. This is the version for the arithmetic expression.

This function is recursive over all objects that can be proved and creates the tree of proof for a clause.

Specified by:

getSolver in interface Clause

Parameters:

rules - the RuleSet object containing the rules of knowledge.

parentSolution - the solution known so far at the parent node.

Returns:

the node of the tree of proof.

See Also:

Clause.getSolver(RuleSet, SubstitutionSet, AbstractSolutionNode)

replaceVariables

public Arithmetic replaceVariables(SubstitutionSet s)

Replaces all the variables in the arithmetic expression according to the specified bindings.

This method is recursive over all PCExpression implementations.

Specified by:

replaceVariables in interface PCExpression

Parameters:

s - the SubstitutionSet that contains the bindings of the variables so far.

Returns:

a Arithmetic object representing the bound arithmetic expression.

See Also:

PCExpression.replaceVariables(model.SubstitutionSet)

standardizeVariablesApart

public Arithmetic standardizeVariablesApart(Hashtable<Variable,Variable> newVars)

Standardizes the variables in order to be sure that there won't be any variable clashes.

This method is recursive over all PCExpression implementations.

Specified by:

standardizeVariablesApart in interface PCExpression

Parameters:

newVars - is a parameter to save over the recursion all the variable replacements done so far.

Returns:

a Arithmetic object representing the standardized arithmetic expression.

See Also:

PCExpression.standardizeVariablesApart(java.util.Hashtable)

toString

public String toString()

Returns the arithmetic expression under the form of: "operand1 'symbol' operand2".

Overrides:

toString in class Object

See Also:

Object.toString()