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| <p>'''The Signs of Inclusion, Equality, Etc.'''</p> | | <p>'''The Signs of Inclusion, Equality, Etc.'''</p> |
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− | <p>I shall follow Boole in taking the sign of equality to signify identity. Thus, if v denotes the Vice-President of the United States, and p the President of the Senate of the United States,</p> | + | <p>I shall follow Boole in taking the sign of equality to signify identity. Thus, if <math>v\!</math> denotes the Vice-President of the United States, and <math>p\!</math> the President of the Senate of the United States,</p> |
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− | <p>v = p</p> | + | | align="center" | <math>v = p\!</math> |
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| <p>means that every Vice-President of the United States is President of the Senate, and every President of the United States Senate is Vice-President.</p> | | <p>means that every Vice-President of the United States is President of the Senate, and every President of the United States Senate is Vice-President.</p> |
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| <p>The sign "less than" is to be so taken that</p> | | <p>The sign "less than" is to be so taken that</p> |
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− | <p>f < m</p> | + | | align="center" | <math>f < m\!</math> |
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| <p>means that every Frenchman is a man, but there are men besides Frenchmen.</p> | | <p>means that every Frenchman is a man, but there are men besides Frenchmen.</p> |
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− | <p>Drobisch has used this sign in the same sense. It will follow from these significations of '=' and '<' that the sign '-<' (or '=<', "as small as") will mean "is". Thus,</p> | + | <p>Drobisch has used this sign in the same sense. It will follow from these significations of <math>=\!</math> and <math><\!</math> that the sign <math>-\!\!\!<\!</math> (or <math>\leqq,</math> "as small as") will mean "is". Thus,</p> |
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− | <p>f -< m</p> | + | | align="center" | <math>f -\!\!\!< m</math> |
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| <p>means "every Frenchman is a man", without saying whether there are any other men or not. So,</p> | | <p>means "every Frenchman is a man", without saying whether there are any other men or not. So,</p> |
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− | <p>'m' -< 'l'</p> | + | | align="center" | <math>m -\!\!\!< l</math> |
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− | <p>will mean that every mother of anything is a lover of the same thing; although this interpretation in some degree anticipates a convention to be made further on. These significations of '=' and '<' plainly conform to the indispensable conditions. Upon the transitive character of these relations the syllogism depends, for by virtue of it, from</p> | + | | |
| + | <p>will mean that every mother of anything is a lover of the same thing; although this interpretation in some degree anticipates a convention to be made further on. These significations of <math>=\!</math> and <math><\!</math> plainly conform to the indispensable conditions. Upon the transitive character of these relations the syllogism depends, for by virtue of it, from</p> |
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| <p>f -< m</p> | | <p>f -< m</p> |