org.sosy_lab.solver.basicimpl.tactics

Enum Tactic

java.lang.Object

java.lang.Enum<Tactic>

org.sosy_lab.solver.basicimpl.tactics.Tactic

All Implemented Interfaces:

Serializable, Comparable<Tactic>

public enum Tactic
extends Enum<Tactic>

Tactic is a generic formula to formula transformation.

Depending on whether the chosen solver supports the transformation, at runtime switches between solver-provided implementation and our own generic visitor-based one.

Tactics can be applied using FormulaManager.applyTactic(org.sosy_lab.solver.api.BooleanFormula, org.sosy_lab.solver.basicimpl.tactics.Tactic)

Enum Constant Summary

Enum Constants

Enum Constant and Description
ACKERMANNIZATION Replaces all applications of UFs with fresh variables and adds constraints to enforce the functional consistency.
NNF Convert the formula to NNF (negated normal form).
QE_LIGHT Perform "best-effort" quantifier elimination: when the bound variable can be "cheaply" eliminated using a pattern-matching approach, eliminate it, and otherwise leave it as-is.
TSEITIN_CNF Convert the formula to CNF (conjunctive normal form), using extra fresh variables to avoid the size explosion.

Method Summary

Modifier and Type	Method and Description
static Tactic	valueOf(String name) Returns the enum constant of this type with the specified name.
static Tactic[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ACKERMANNIZATION

public static final Tactic ACKERMANNIZATION

Replaces all applications of UFs with fresh variables and adds constraints to enforce the functional consistency. Quantified formulas are not supported.

NNF

public static final Tactic NNF

Convert the formula to NNF (negated normal form).

TSEITIN_CNF

public static final Tactic TSEITIN_CNF

Convert the formula to CNF (conjunctive normal form), using extra fresh variables to avoid the size explosion. The resulting formula is not equivalent but only equisatisfiable to the original one.

NB: currently this tactic does not have default implementation.

QE_LIGHT

public static final Tactic QE_LIGHT

Perform "best-effort" quantifier elimination: when the bound variable can be "cheaply" eliminated using a pattern-matching approach, eliminate it, and otherwise leave it as-is.

Method Detail

values

public static Tactic[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Tactic c : Tactic.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Tactic valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null