What it means
x ∈ A says x belongs to the set A. With a stroke, ∉, it says x does not.
Read aloud in real formulas
x ∈ ℝ
Aethel says
x is in the real numbers
x is a real number
3 ∉ {1, 2}
Aethel says
3 is not in the set 1, 2
3 is not in the set {1, 2}
Typing it
- LaTeX
- \in, \notin
- Unicode
- U+2208, U+2209
Questions
How do you say ∈ out loud?
It is usually read “is in”, and also “is an element of” or “belongs to”.
What does ∈ mean in maths?
x ∈ A says x belongs to the set A. With a stroke, ∉, it says x does not.
How do you type ∈?
In LaTeX, write \in, \notin. Its Unicode code point is U+2208, U+2209.
What is ∈ often confused with?
It is easy to mistake for the Greek letter ε (epsilon), which it was originally drawn from.