Class SpecialFormula

All Implemented Interfaces:
Formula, ClassicalFormula, ComplexLogicalFormula, Conjunctable, Disjunctable, Invertable, LogicStructure, ProbabilityAware, QuantifiedFormula, SimpleLogicalFormula
Direct Known Subclasses:
Contradiction, Tautology

public abstract class SpecialFormula extends FolFormula
This class captures the common functionalities of the special formulas tautology and contradiction.
Author:
Matthias Thimm
  • Constructor Details

    • SpecialFormula

      public SpecialFormula()
  • Method Details

    • containsQuantifier

      public boolean containsQuantifier()
      Description copied from interface: QuantifiedFormula
      Checks whether this formula contains any quantification.
      Returns:
      "true" if this formula contains a quantification.
    • getTerms

      public Set<Term<?>> getTerms()
      Returns:
      a set containing all terms of this logical structure
    • getTerms

      public <C extends Term<?>> Set<C> getTerms(Class<C> cls)
      Description copied from interface: LogicStructure
      Processes the set containing all terms of type C. This method uses the equals method of the given Class and therefore does not add terms which are sub classes of type C to the set.
      Type Parameters:
      C - the type of terms
      Parameters:
      cls - The Class structure containing type information about the searched term
      Returns:
      A set containing all terms of type C of this logical structure
    • getAtoms

      public Set<FolAtom> getAtoms()
      Description copied from interface: SimpleLogicalFormula
      Processes the set of all atoms which appear in this formula
      Specified by:
      getAtoms in interface SimpleLogicalFormula
      Specified by:
      getAtoms in class RelationalFormula
      Returns:
      all atoms that appear in this formula.
    • getPredicates

      public Set<Predicate> getPredicates()
      Description copied from interface: SimpleLogicalFormula
      Processes the set of all predicates which appear in this formula
      Returns:
      all predicates that appear in this formula
    • isClosed

      public boolean isClosed()
      Description copied from interface: QuantifiedFormula
      Checks whether this formula is closed, i.e. whether every variables occurring in the formula is bound by a quantifier.
      Returns:
      "true" if this formula is closed, "false" otherwise.
    • isClosed

      public boolean isClosed(Set<Variable> boundVariables)
      Description copied from interface: QuantifiedFormula
      Checks whether this formula is closed, i.e. whether every variables occurring in the formula is bound by a quantifier. Every variable in "boundVariables" is already assumed to be bound.
      Parameters:
      boundVariables - the variables assumed to be bound.
      Returns:
      "true" if this formula is closed wrt. "boundVariables", "false" otherwise.
    • isWellBound

      public boolean isWellBound()
      Description copied from interface: QuantifiedFormula
      Checks whether this formula is well-bound, i.e. whether no variable bound by a quantifier is again bound by another quantifier within the first quantifier's range.
      Returns:
      "true" if this formula is well-bound, "false" otherwise.
    • isWellBound

      public boolean isWellBound(Set<Variable> boundVariables)
      Description copied from interface: QuantifiedFormula
      Checks whether this formula is well-bound, i.e. whether no variable bound by a quantifier is again bound by another quantifier within the first quantifier range. Every variable in "boundVariables" is assumed to be bound already.
      Parameters:
      boundVariables - the variables assumed to be bound.
      Returns:
      "true" if this formula is well-bound, "false" otherwise.
    • isLiteral

      public boolean isLiteral()
      Returns:
      true if the formula represents a literal in the language or false otherwise
    • substitute

      public FolFormula substitute(Term<?> v, Term<?> t)
      Description copied from class: RelationalFormula
      Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula. NOTE: if "v" is a variable and bound to a quantifier then "v" is not substituted in that quantifiers inner formula.
      Specified by:
      substitute in interface ComplexLogicalFormula
      Specified by:
      substitute in class FolFormula
      Parameters:
      v - the term to be substituted.
      t - the term to substitute.
      Returns:
      a formula where every occurrence of "v" is replaced by "t".
    • getUnboundVariables

      public Set<Variable> getUnboundVariables()
      Returns:
      a set of of unbound variables
    • getFunctors

      public Set<Functor> getFunctors()
      Specified by:
      getFunctors in class RelationalFormula
      Returns:
      all functors that appear in this formula.
    • getQuantifiedFormulas

      public Set<FolFormula> getQuantifiedFormulas()
      Returns:
      formulas
    • getDisjunctions

      public Set<Disjunction> getDisjunctions()
      Returns:
      disjunction
    • getConjunctions

      public Set<Conjunction> getConjunctions()
      Returns:
      conjunctions
    • isDnf

      public boolean isDnf()
      Description copied from class: FolFormula
      Checks whether this formula is in disjunctive normal form.
      Specified by:
      isDnf in class FolFormula
      Returns:
      "true" iff this formula is in disjunctive normal form.
    • toNnf

      public FolFormula toNnf()
      Description copied from class: FolFormula
      Makes the negation normal form of this formula.
      Specified by:
      toNnf in class FolFormula
      Returns:
      the NNF of this formula
    • collapseAssociativeFormulas

      public FolFormula collapseAssociativeFormulas()
      Description copied from class: FolFormula
      This method collapses all associative operations appearing in this term, e.g. every a||(b||c) becomes a||b||c.
      Specified by:
      collapseAssociativeFormulas in class FolFormula
      Returns:
      the collapsed formula.