Packages

class TransformToCnf extends CnfBuilder

Plaisted transformation: used for conversion of a propositional formula into conjunctive normal form (CNF) (input format for SAT solver). A simple conversion into CNF via Shannon expansion would also be possible but it's worst-case complexity is exponential (in the number of variables) and thus even simple problems could become untractable. The Plaisted transformation results in an _equisatisfiable_ CNF-formula (it generates auxiliary variables) but runs with linear complexity. The common known Tseitin transformation uses bi-implication, whereas the Plaisted transformation uses implication only, thus the resulting CNF formula has (on average) only half of the clauses of a Tseitin transformation. The Plaisted transformation uses the polarities of sub-expressions to figure out which part of the bi-implication can be omitted. However, if all sub-expressions have positive polarity (e.g., after transformation into negation normal form) then the conversion is rather simple and the pseudo-normalization via NNF increases chances only one side of the bi-implication is needed.

Linear Supertypes
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. TransformToCnf
  2. CnfBuilder
  3. AnyRef
  4. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Instance Constructors

  1. new TransformToCnf(symbolMapping: SymbolMapping)

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def addClauseProcessed(clause: Clause): Unit
    Definition Classes
    CnfBuilder
  5. def apply(p: CNF.Prop): Solvable
  6. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. def buildCnf: Array[Clause]
    Definition Classes
    CnfBuilder
  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  9. def constFalse: Lit
    Definition Classes
    CnfBuilder
  10. lazy val constTrue: Lit
    Definition Classes
    CnfBuilder
  11. def convertSym(sym: CNF.Sym): Lit
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  14. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  15. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  16. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  17. def isConst(l: Lit): Boolean
    Definition Classes
    CnfBuilder
  18. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  19. var literalCount: Int
    Definition Classes
    TransformToCnfCnfBuilder
  20. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  21. def newLiteral(): Lit

    returns

    new Tseitin variable

    Definition Classes
    CnfBuilder
  22. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  23. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  24. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  25. def toString(): String
    Definition Classes
    AnyRef → Any
  26. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  27. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  28. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()

Inherited from CnfBuilder

Inherited from AnyRef

Inherited from Any

Ungrouped