27 lines
688 B
Markdown
27 lines
688 B
Markdown
Page 515
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**Test Yourself**
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1. If $R$ is a relation from $A$ to $B$, $x \in A$, and $y \in B$, the notation
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$x R y$ means that ____.
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$x$ is related to $y$ by $R$
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2. If $R$ is a relation from $A$ to $B$, $x \in A$, and $y \in B$, the notation
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$x \cancel{R} y$ means that ____.
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$x$ is not related to $y$ by $R$.
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3. If $R$ is a relation from $A$ to $B$, $x \in A$, and $y \in B$, the notation
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$(y, x) \in R^{-1}$ if, and only if, ____.
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$$ (x, y) \in R $$
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4. A relation on a set $A$ is a relation from ____ to ____.
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$A$; $A$
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5. If $R$ is a relation on a set $A$, the directed graph of $R$ has an arrow
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from $x$ to $y$ if, and only if, ____.
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$x$ is related to $y$ by $R$
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