Exercise · ZW-BINARY-RELATION-001 · ★☆☆ Basic
What is a binary relation from \(A\) to \(B\)?
Choose one option.
Show answer
- A. A subset of \(A \times B\)
Explanation
A relation from \(A\) to \(B\) is a set of pairs \((a,b)\) with \(a\in A\) and \(b\in B\), that is, a subset of \(A\times B\). A single pair is not enough.
Review the concept: Binary relation
A set of ordered pairs \((a,b)\) specifying which elements of \(A\) are related to which elements of \(B\).
\[R \subseteq A \times B\]
More practice problems: binary relation
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- ZW-BINARY-RELATION-004 If R=\(1,2),(2,3)\, what is the range of R?
- ZW-BINARY-RELATION-005 What is the usual notation for saying that a is related to b by R?
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- ZW-BINARY-RELATION-008 Let R=\(a,b)∈ ℕ×ℕ : b=a+1\. Which of these pairs belongs to R?
- ZW-BINARY-RELATION-009 A relation R on A is reflexive if (a,a)∈ R for every a∈ A. With A=\1,2,3\, how many reflexive relat…