# Page:Carroll - Game of Logic.djvu/65

§ 6.]
49
CROSS QUESTIONS.
Taking "rabbits" as Universe; ${\displaystyle m}$ = "greedy";
${\displaystyle x}$ = "old"; and ${\displaystyle y}$ = "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; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ All black rabbits are greedy.
6.  All rabbits, that are not greedy, are black; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ No old rabbits are free from greediness.

Taking "birds" as Universe; ${\displaystyle m}$ = "that sing loud";
${\displaystyle x}$ = "well-fed"; and ${\displaystyle y}$ = "happy"; represent
1.  All well-fed birds sing loud; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ No birds, that sing loud, are unhappy.
2.  All birds, that do not sing loud, are unhappy; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ No well-fed birds fail to sing loud.

Taking "persons" as Universe; ${\displaystyle m}$ = "in the house";
${\displaystyle x}$ = "John"; and ${\displaystyle y}$ = "having a tooth-ache"; represent
1.  John is in the house; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ Everybody in the house is suffering from tooth-ache.
2.  There is no one in the house but John; ${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}}$ Nobody, out of the house, has a tooth-ache.

[See pp. 68–70]