Set difference
High school
Consider1 two sets $A$ and $B$. The set difference $A \setminus B$ is the set of elements of $A$ that are not in $B$.
Examples
Worked examples
- $A = \setdef{1, 2}$ and $B = \setdef{3, 4}$ : $A \setminus B = \setdef{1, 2}$ Elementary
Examples
-
$\setdef{1, 2, 3} \setminus \setdef{2} = \setdef{1, 3}$
Elementary
$\setdef{1, 2, 3} \setminus \setdef{2}$ is a set difference because it removes the elements of $\setdef{2}$ from $\setdef{1, 2, 3}$.
Distinctions involving this term
- Types of difference: Many quantities compare two things by “how far apart” they are. A difference is the result of subtraction and can be negative. No distance is negative. An error compares an approximation with the truth, a change compares the end with the start, and a set difference removes elements.