blog
Class ImplicFormula

java.lang.Object
  blog.ArgSpec
      blog.Formula
          blog.ImplicFormula

public class ImplicFormula
extends Formula

An implication formula alpha -> beta. It is true if alpha is false or beta is true.

Field Summary

Fields inherited from class blog.Formula

ALL_OBJECTS, NOT_EXPLICIT

Fields inherited from class blog.ArgSpec

location

Constructor Summary

ImplicFormula(Formula antecedent, Formula consequent)
Creates a new ImplicFormula of the form antecedent -> consequent.

Method Summary

boolean	checkTypesAndScope(Model model, java.util.Map scope) Returns true if, within the given scope, all the variables used in this ArgSpec are in scope and all type constraints are satisfied.
boolean	equals(java.lang.Object o)
java.lang.Object	evaluate(EvalContext context) Returns the value of this argument specification in the given context.
Formula	getAntecedent() Returns the antecedent (lefthand side) of this formula.
Formula	getConsequent() Returns the consequent (righthand side) of this formula.
protected Formula	getEquivToNegationInternal() The formula equivalent to the negation of phi -> psi is phi & !psi.
java.util.Set	getNonSatisfiersIfExplicit(EvalContext context, LogicalVar subject, GenericObject genericObj) Returns the set of values for the logical variable subject that are consistent with the generating function values of genericObj and that make this formula false in the given context, if this set can be determined without enumerating possible values for subject.
ConjFormula	getPropCNF() The CNF form of an implication phi -> psi is the CNF form of the equivalent formula !phi | psi.
DisjFormula	getPropDNF() The DNF form of an implication phi -> psi is the DNF form of the equivalent formula !phi | psi.
java.util.Set	getSatisfiersIfExplicit(EvalContext context, LogicalVar subject, GenericObject genericObj) Returns the set of values for the logical variable subject that are consistent with the generating function values of genericObj and that make this formula true in the given context, if this set can be determined without enumerating possible values for subject.
Formula	getStandardForm() The standard form of an implication formula phi -> psi is the standard form of the equivalent formula !phi | psi.
java.util.List	getSubFormulas()
ArgSpec	getSubstResult(Substitution subst, java.util.Set<LogicalVar> boundVars) Returns the result of applying the substitution subst to this expression, excluding the logical variables in boundVars.
int	hashCode()
java.lang.String	toString()

Methods inherited from class blog.Formula

compile, containsAnyTerm, containsRandomSymbol, containsTerm, getEquivToNegation, getGenFuncsApplied, getSubExprs, getSubformulas, getTopLevelTerms, isElementary, isLiteral, isQuantified, isTrue

Methods inherited from class blog.ArgSpec

evaluate, evaluate, getFreeVars, getLocation, getSubstResult, getValueIfNonRandom, getVariable, isDetermined, isNumeric, setLocation

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ImplicFormula

public ImplicFormula(Formula antecedent,
                     Formula consequent)

Creates a new ImplicFormula of the form antecedent -> consequent.

Method Detail

getAntecedent

public Formula getAntecedent()

Returns the antecedent (lefthand side) of this formula.

getConsequent

public Formula getConsequent()

Returns the consequent (righthand side) of this formula.

evaluate

public java.lang.Object evaluate(EvalContext context)

Description copied from class: ArgSpec

Returns the value of this argument specification in the given context. Returns null if the partial world in this context is not complete enough to evaluate this ArgSpec, or if this ArgSpec contains a free variable that is not assigned a value in the given context.

Specified by:

evaluate in class ArgSpec

getStandardForm

public Formula getStandardForm()

The standard form of an implication formula phi -> psi is the standard form of the equivalent formula !phi | psi.

Overrides:

getStandardForm in class Formula

getEquivToNegationInternal

protected Formula getEquivToNegationInternal()

The formula equivalent to the negation of phi -> psi is phi & !psi.

Overrides:

getEquivToNegationInternal in class Formula

getSubFormulas

public java.util.List getSubFormulas()

getPropCNF

public ConjFormula getPropCNF()

The CNF form of an implication phi -> psi is the CNF form of the equivalent formula !phi | psi.

Overrides:

getPropCNF in class Formula

getPropDNF

public DisjFormula getPropDNF()

The DNF form of an implication phi -> psi is the DNF form of the equivalent formula !phi | psi.

Overrides:

getPropDNF in class Formula

getSatisfiersIfExplicit

public java.util.Set getSatisfiersIfExplicit(EvalContext context,
                                             LogicalVar subject,
                                             GenericObject genericObj)

Description copied from class: Formula

Returns the set of values for the logical variable subject that are consistent with the generating function values of genericObj and that make this formula true in the given context, if this set can be determined without enumerating possible values for subject. Returns the special value Formula.NOT_EXPLICIT if determining the desired set would requiring enumerating possible values for subject. Also, returns the special value Formula.ALL_OBJECTS if this formula is true in the given context for all objects consistent with genericObj. Finally, returns null if it tries to access an uninstantiated random variable.

Specified by:

getSatisfiersIfExplicit in class Formula

Parameters:

context - an evaluation context that does not assign a value to the logical variable subject

subject - a logical variable

genericObj - a GenericObject instance, which can stand for any object of a given type or include values for certain generating functions

getNonSatisfiersIfExplicit

public java.util.Set getNonSatisfiersIfExplicit(EvalContext context,
                                                LogicalVar subject,
                                                GenericObject genericObj)

Description copied from class: Formula

Returns the set of values for the logical variable subject that are consistent with the generating function values of genericObj and that make this formula false in the given context, if this set can be determined without enumerating possible values for subject. Returns the special value Formula.NOT_EXPLICIT if determining the desired set would requiring enumerating possible values for subject. Also, returns the special value Formula.ALL_OBJECTS if this formula is false in the given context for all objects consistent with genericObj. Finally, returns null if it tries to access an uninstantiated random variable.

This default implementation calls getEquivToNegation, then calls getSatisfiersIfExplicit on the resulting formula. Warning: subclasses must override either this method or getEquivToNegationInternal to avoid an UnsupportedOperationException.

Overrides:

getNonSatisfiersIfExplicit in class Formula

Parameters:

context - an evaluation context that does not assign a value to the logical variable subject

subject - a logical variable

genericObj - a GenericObject instance, which can stand for any object of a given type or include values for certain generating functions

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

checkTypesAndScope

public boolean checkTypesAndScope(Model model,
                                  java.util.Map scope)

Description copied from class: ArgSpec

Returns true if, within the given scope, all the variables used in this ArgSpec are in scope and all type constraints are satisfied. If there is a type or scope error, prints an appropriate message to standard error and returns false.

Specified by:

checkTypesAndScope in class ArgSpec

scope - a Map from variable names (Strings) to LogicalVar objects

getSubstResult

public ArgSpec getSubstResult(Substitution subst,
                              java.util.Set<LogicalVar> boundVars)

Description copied from class: ArgSpec

Returns the result of applying the substitution subst to this expression, excluding the logical variables in boundVars. This method is used for recursive calls. The set boundVars should contain those variables that are bound in the syntax tree between this sub-expression and the top-level expression to which the substitution is being applied.

Specified by:

getSubstResult in class ArgSpec