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Page:Carroll - Game of Logic.djvu/65

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§ 6.]
49
CROSS QUESTIONS.
Taking "rabbits" as Universe; = "greedy";
= "old"; and = "black"; represent
  1. No old rabbits are greedy.
  2. Some not-greedy rabbits are black.
  3. All white rabbits are free from greediness.
  4. All greedy rabbits are young.
  5. No old rabbits are greedy;
    All black rabbits are greedy.
  6. All rabbits, that are not greedy, are black;
    No old rabbits are free from greediness.
 

 
Taking "birds" as Universe; = "that sing loud";
= "well-fed"; and = "happy"; represent
  1. All well-fed birds sing loud;
    No birds, that sing loud, are unhappy.
  2. All birds, that do not sing loud, are unhappy;
    No well-fed birds fail to sing loud.
 

 
Taking "persons" as Universe; = "in the house";
= "John"; and = "having a tooth-ache"; represent
  1. John is in the house;
    Everybody in the house is suffering from tooth-ache.
  2. There is no one in the house but John;
    Nobody, out of the house, has a tooth-ache.
 

 

[See pp. 68–70]