Class: Syllogism

Inherits:
Object
  • Object
show all
Defined in:
lib/catlogic/syllogism.rb

Overview

Class for any syllogism object.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(major, minor, conclusion = nil) ⇒ Syllogism

Syllogism object initiation takes three Proposition objects



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# File 'lib/catlogic/syllogism.rb', line 7

def initialize(major, minor, conclusion=nil)
  @major = major
  @minor = minor
  if conclusion == nil
    @conclusion = self.getComputedConclusion
  else
    @conclusion = conclusion
  end
end

Instance Attribute Details

#conclusion ⇒ Object (readonly)

Returns the value of attribute conclusion.



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# File 'lib/catlogic/syllogism.rb', line 3

def conclusion
  @conclusion
end

#major ⇒ Object (readonly)

Returns the value of attribute major.



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# File 'lib/catlogic/syllogism.rb', line 3

def major
  @major
end

#minor ⇒ Object (readonly)

Returns the value of attribute minor.



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# File 'lib/catlogic/syllogism.rb', line 3

def minor
  @minor
end

Instance Method Details

#affirm_from_neg_test ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 130

def affirm_from_neg_test
  if (@major.quality.label == 'negative' || @minor.quality.label == 'negative') && @conclusion.quality.label != 'negative'
    validity = false
  else
    validity = true
  end
end

#displayPropositionalForm ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 167

def displayPropositionalForm
  form = Form.new(self.mood, self.figure)
  form.displayPropositionalForm
end

#exclusive_premises_test ⇒ Object

exclusive premises



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# File 'lib/catlogic/syllogism.rb', line 122

def exclusive_premises_test
  if @major.quality.label == 'negative' && @minor.quality.label == 'negative'
    validity = false
  else
    validity = true
  end
end

#figure ⇒ Object

gets the Figure of Syllogism (e.g. 1, 2, 3, 4)



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# File 'lib/catlogic/syllogism.rb', line 73

def figure
  mjmp = @major.position_of_term(self.middle)
  mnmp = @minor.position_of_term(self.middle)

  if mjmp == 'subject' && mnmp == 'predicate'
    figure = Figure.new(1)
  elsif mjmp == 'predicate' && mnmp == 'predicate'
    figure = Figure.new(2)
  elsif mjmp ==   'subject' && mnmp == 'subject'
    figure = Figure.new(3)
  elsif mjmp == 'predicate' && mnmp == 'subject'
    figure = Figure.new(4)
  end
  return figure
end

#form ⇒ Object

Retrieve Form object of the Syllogism (i.e. AAAI, EAI4)



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# File 'lib/catlogic/syllogism.rb', line 90

def form
  form = Form.new(self.mood, self.figure)
  return form
end

#illicit_major_test ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 105

def illicit_major_test
  ##Rule Number 2a distribution of major term
  if @conclusion.distribution('predicate').label == 'distributed' && @major.distribution(@major.position_of_term(self.majorterm)).label != 'distributed'
    validity = false
  else
    validity = true
  end
end

#illicit_minor_test ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 113

def illicit_minor_test
  ##Rule Number 2b distribution of minor term - check fallacy of illicit minor
  if @conclusion.distribution('subject').label == 'distributed' && @minor.distribution(@minor.position_of_term(self.minorterm)).label != 'distributed'
    validity = false
  else
    validty = true
  end
end

#label ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 157

def label
  return "#{@major.label}\n#{@minor.label}\n#{@conclusion.label}"
end

#majorterm ⇒ Object

gets the major term as a String from the major premise by identifying the middle term and then identifying the term in the premise that is not the middle



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# File 'lib/catlogic/syllogism.rb', line 47

def majorterm
  if @major.subject.label == self.middle.label
    majorterm = @major.predicate
  else
    majorterm = @major.subject
  end
  majorterm
end

#middle ⇒ Object

This method gets the middle term by looking for the term in the major and minor terms that are used twice.



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# File 'lib/catlogic/syllogism.rb', line 18

def middle
  termarray = [@major.subject.label, @major.predicate.label, @minor.subject.label, @minor.predicate.label]
  middle = nil
  if self.three_term?
    termarray.detect do |term|
      if termarray.count(term) == 2
        middle = Term.new(term)
      end
    end
  else
    middle = "Error: this is not a three term syllogism"
  end
  middle
end

#minorterm ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 55

def minorterm
  if @minor.subject.label == self.middle.label
    minorterm = @minor.predicate
  else
    minorterm = @minor.subject
  end
  minorterm
end

#mood ⇒ Object

returns the Mood object of Syllogism (e.g. AAA, EEE)



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# File 'lib/catlogic/syllogism.rb', line 66

def mood
  mood = Mood.new(@major.type, @minor.type, @conclusion.type)
  return mood
end

#neg_from_affirms_test ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 138

def neg_from_affirms_test
  if (@conclusion.quality.label == 'negative' && (@major.quality.label != 'negative' && @minor.quality.label != 'negative'))

    validity = false
    #validity = "pass"
  else
    validity = true
  end
end

#three_term? ⇒ Boolean 



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# File 'lib/catlogic/syllogism.rb', line 33

def three_term?
  termarray = [@major.subject.label, @major.predicate.label, @minor.subject.label, @minor.predicate.label]
  if termarray.uniq.size == 3
    answer = true
  else
    answer = false
  end
end

#undistributed_middle_test ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 95

def undistributed_middle_test
  ## Rule Number 1 - middle distributed
  if @major.distribution(@major.position_of_term(self.middle)).label == 'undistributed' && @minor.distribution(@minor.position_of_term(self.middle)).label == 'undistributed'
    validity = false
  else
    validity = true
  end
  return validity
end

#validity ⇒ Object 



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# File 'lib/catlogic/syllogism.rb', line 149

def validity
  if (self.undistributed_middle_test != true || self.illicit_major_test != true || self.illicit_minor_test != true || self.exclusive_premises_test != true || self.affirm_from_neg_test != true || self.neg_from_affirms_test != true)
    validity = false
  else
    validity = true
  end
end