Package org.tweetyproject.logics.fol.syntax

Class Implication

java.lang.Object
org.tweetyproject.logics.commons.syntax.RelationalFormula
org.tweetyproject.logics.fol.syntax.FolFormula
org.tweetyproject.logics.fol.syntax.Implication
All Implemented Interfaces:
Formula, ClassicalFormula, ComplexLogicalFormula, Conjunctable, Disjunctable, Invertable, LogicStructure, ProbabilityAware, QuantifiedFormula, SimpleLogicalFormula
public class Implication extends FolFormula
The implication of first-order logic.
Author:
Anna Gessler

  • Constructor Details

    • Implication

      public Implication(RelationalFormula a, RelationalFormula b)
      Creates a new implication a=>b with the two given formulas
      Parameters:
      a - a relational formula.
      b - a relational formula.

    • Implication

      public Implication(Pair<RelationalFormula,RelationalFormula> formulas)
      Creates a new implication with the given pair of formulas
      Parameters:
      formulas - a pair of formulas

  • Method Details

    • getFormulas

      public Pair<RelationalFormula,RelationalFormula> getFormulas()
      Returns the formulas of the implication.
      Returns:
      the formulas that are part of the implication

    • setFormulas

      public void setFormulas(Pair<RelationalFormula,RelationalFormula> formulas)
      Sets the formulas of the implication.
      Parameters:
      formulas - the formulas

    • setFormulas

      public void setFormulas(RelationalFormula left, RelationalFormula right)
      Sets the formulas of the implication.
      Parameters:
      left - left formula
      right - right formula

    • setFirstFormula

      public void setFirstFormula(RelationalFormula left)
      Sets the left side formula of the implication left => right
      Parameters:
      left - formula.

    • setSecondFormula

      public void setSecondFormula(RelationalFormula right)
      Sets the right side formula of the implication left => right
      Parameters:
      right - formula.

    • getFirstFormula

      public RelationalFormula getFirstFormula()
      Get the left side formula of the implication left => right.
      Returns:
      the 1st relational formula

    • getSecondFormula

      public RelationalFormula getSecondFormula()
      Get the right side formula of the implication left => right
      Returns:
      the second relational formula

    • getPredicates

      public Set<? extends 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

    • isLiteral

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

    • getUnboundVariables

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

    • containsQuantifier

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

    • 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.

    • 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.

    • 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

    • 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 RelationalFormula 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.

    • 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.

    • substitute

      public FolFormula substitute(Term<?> v, Term<?> t) throws IllegalArgumentException
      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".
      Throws:
      IllegalArgumentException - if "v" and "t" are of different sorts (NOTE: this exception is only thrown when "v" actually appears in this formula).

    • clone

      public Implication clone()
      Description copied from interface: SimpleLogicalFormula
      Creates a deep copy of this formula
      Specified by:
      clone in interface ComplexLogicalFormula
      Specified by:
      clone in interface SimpleLogicalFormula
      Specified by:
      clone in class FolFormula
      Returns:
      the cloned formula

    • getAtoms

      public Set<? extends Atom> 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.

    • getFunctors

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

    • toString

      public String toString()
      Specified by:
      toString in class RelationalFormula

    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface SimpleLogicalFormula
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Specified by:
      equals in interface SimpleLogicalFormula
      Overrides:
      equals in class Object