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Line 2,745: |
| |} | | |} |
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− | The ''relative complement'' of <math>X\!</math> in <math>Y,\!</math> for two sets <math>X, Y \subseteq U,</math> written as <math>^{\backprime\backprime} \, Y\!-\!X \, ^{\prime\prime},</math> is the set of elements in <math>Y\!</math> that are not in <math>X,\!</math> that is: | + | The ''relative complement'' of <math>P\!</math> in <math>Q,\!</math> for two sets <math>P, Q \subseteq X,</math> is denoted by <math>^{\backprime\backprime} \, Q\!-\!P \, ^{\prime\prime}</math> and defined as the set of elements in <math>Q\!</math> that do not belong to <math>P,\!</math> that is: |
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| {| align="center" cellpadding="8" width="90%" | | {| align="center" cellpadding="8" width="90%" |
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| <math>\begin{array}{lll} | | <math>\begin{array}{lll} |
− | Y\!-\!X
| + | Q\!-\!P |
| & = & | | & = & |
− | \{ \, u \in U : u \in Y\ \operatorname{and}\ \underline{(} u \in X \underline{)} \, \}. | + | \{ \, x \in X : x \in Q ~\operatorname{and}~ \underline{(} x \in P \underline{)} \, \}. |
| \\ | | \\ |
| \end{array}</math> | | \end{array}</math> |
| |} | | |} |
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− | The ''intersection'' of <math>X\!</math> and <math>Y,\!</math> for two sets <math>X, Y \subseteq U,</math> is denoted by <math>^{\backprime\backprime} \, X \cap Y \, ^{\prime\prime},</math> and defined as the set of elements in <math>U\!</math> that belong to both of <math>X\!</math> and <math>Y.\!</math> | + | The ''intersection'' of <math>P\!</math> and <math>Q,\!</math> for two sets <math>P, Q \subseteq X,</math> is denoted by <math>^{\backprime\backprime} \, P \cap Q \, ^{\prime\prime}</math> and defined as the set of elements in <math>X\!</math> that belong to both <math>P\!</math> and <math>Q.\!</math> |
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| {| align="center" cellpadding="8" width="90%" | | {| align="center" cellpadding="8" width="90%" |
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| <math>\begin{array}{lll} | | <math>\begin{array}{lll} |
− | X \cap Y
| + | P \cap Q |
| & = & | | & = & |
− | \{ \, u \in U : u \in X\ \operatorname{and}\ u \in Y \, \}. | + | \{ \, x \in X : x \in P ~\operatorname{and}~ x \in Q \, \}. |
| \\ | | \\ |
| \end{array}</math> | | \end{array}</math> |