org.qedeq.kernel.bo.logic
Class FormulaChecker

java.lang.Object
  org.qedeq.kernel.bo.logic.FormulaChecker

public final class FormulaChecker

extends Object

This class deals with Elements which represent a formula. It has methods to check those elements for certain criteria.

Version:

$Revision: 1.4 $

Field Summary

static String	CONJUNCTION_OPERATOR Operator string for logical "and".
static String	DISJUNCTION_OPERATOR Operator string for logical "or".
static String	EQUIVALENCE_OPERATOR Operator string for logical equivalence.
static String	EXISTENTIAL_QUANTIFIER_OPERATOR Operator string for logical "exists" operator.
static String	IMPLICATION_OPERATOR Operator string for logical implication.
static String	LIST_OPERATOR Operator string for predicate argument list.
static String	NEGATION_OPERATOR Operator string for logical negation.
static String	PREDICATE_OPERATOR Operator string for predicate constants.
static String	PREDICATE_VARIABLE_OPERATOR Operator string for predicate variables.
static String	PROPOSITION_VARIABLE_OPERATOR Operator string for proposition variables.
static String	SUBJECT_VARIABLE_OPERATOR Operator string for subject variables.
static String	UNIVERSAL_QUANTIFIER_OPERATOR Operator string for logical "all" operator.

Method Summary

static void	checkFormula(Element element) Is Element a formula?
static void	checkSubjectVariable(Element element) Is Element an subject variable?
static ElementSet	getBoundSubjectVariables(Element element) Return all bound subject variables of an element.
static ElementSet	getFreeSubjectVariables(Element element) Return all free subject variables of an element.
static boolean	isSubjectVariable(Element element) Is Element an subject variable?

Methods inherited from class java.lang.Object

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

Field Detail

CONJUNCTION_OPERATOR

public static final String CONJUNCTION_OPERATOR

Operator string for logical "and".

See Also:

Constant Field Values

DISJUNCTION_OPERATOR

public static final String DISJUNCTION_OPERATOR

Operator string for logical "or".

See Also:

Constant Field Values

IMPLICATION_OPERATOR

public static final String IMPLICATION_OPERATOR

Operator string for logical implication.

See Also:

Constant Field Values

EQUIVALENCE_OPERATOR

public static final String EQUIVALENCE_OPERATOR

Operator string for logical equivalence.

See Also:

Constant Field Values

NEGATION_OPERATOR

public static final String NEGATION_OPERATOR

Operator string for logical negation.

See Also:

Constant Field Values

PREDICATE_OPERATOR

public static final String PREDICATE_OPERATOR

Operator string for predicate constants.

See Also:

Constant Field Values

SUBJECT_VARIABLE_OPERATOR

public static final String SUBJECT_VARIABLE_OPERATOR

Operator string for subject variables.

See Also:

Constant Field Values

PROPOSITION_VARIABLE_OPERATOR

public static final String PROPOSITION_VARIABLE_OPERATOR

Operator string for proposition variables.

See Also:

Constant Field Values

PREDICATE_VARIABLE_OPERATOR

public static final String PREDICATE_VARIABLE_OPERATOR

Operator string for predicate variables.

See Also:

Constant Field Values

LIST_OPERATOR

public static final String LIST_OPERATOR

Operator string for predicate argument list.

See Also:

Constant Field Values

UNIVERSAL_QUANTIFIER_OPERATOR

public static final String UNIVERSAL_QUANTIFIER_OPERATOR

Operator string for logical "all" operator.

See Also:

Constant Field Values

EXISTENTIAL_QUANTIFIER_OPERATOR

public static final String EXISTENTIAL_QUANTIFIER_OPERATOR

Operator string for logical "exists" operator.

See Also:

Constant Field Values

Method Detail

checkFormula

public static final void checkFormula(Element element)
                               throws CheckException

Is Element a formula?

Parameters:

element - check this element

Throws:

CheckException - if it is no formula

isSubjectVariable

public static final boolean isSubjectVariable(Element element)

Is Element an subject variable?

Parameters:

element - check this element

Returns:

is is an atomic element

checkSubjectVariable

public static final void checkSubjectVariable(Element element)
                                       throws CheckException

Is Element an subject variable?

Parameters:

element - check this element

Throws:

CheckException - if it is no subject variable

getFreeSubjectVariables

public static final ElementSet getFreeSubjectVariables(Element element)

Return all free subject variables of an element.

Parameters:

element - check this element

Returns:

all free subject variables

getBoundSubjectVariables

public static final ElementSet getBoundSubjectVariables(Element element)

Return all bound subject variables of an element.

Parameters:

element - check this element

Returns:

all bound subject variables