Not An Element Of Symbol
∉ means “not an element of,” stating that an item does not belong to a set.
U+2209
The symbol ∉ is a standard mathematical notation used to describe membership. It’s often read as “not an element of” when working with sets and logic. You can copy it directly or use its Unicode value U+2209.
Not An Element Of Symbol Meaning
∉ (Unicode U+2209) is pronounced “not an element of.” It is used to state that a particular item is not a member of a set, often in set theory and logic. For example, you might write that x ∉ A to indicate x is not contained in set A. The symbol is also commonly paired with the related “element of” symbol (∈) when contrasting membership vs. non-membership. In documents, it helps communicate restrictions clearly, especially in textbooks, proofs, and formulas where set membership is essential.
Common uses
- •Writing set membership rules, such as x ∉ A
- •Expressing constraints in math problems and solutions
- •Indicating exclusion in formal definitions and logic statements
- •Labeling conditions in exercises, proofs, and worksheets
- •Building clear notation in educational and technical documents
Examples
∉ Not an Element of Symbol (U+2209)
- ∉x ∉ A
- ∉3 ∉ B
- ∉y ∉ S
- ∉z ∉ {1,2,3}
- ∉t ∉ U
Variations
Ready to copy
Technical codes
| Unicode | U+2209 | |
| HTML Entity | ∉ | |
| HTML Code | ∉ | |
| CSS | \2209 |
FAQ
What does ∉ mean?
∉ means “not an element of,” used to say that something is not a member of a set.
How do I write ∉ using Unicode?
The Unicode code point is U+2209. You can use the HTML entity ∉.
Is ∉ the opposite of ∈?
Yes. ∈ means “an element of,” while ∉ indicates non-membership in the set.
Where is ∉ commonly used?
It’s most commonly seen in set theory, proofs, and formal logic or math documents that describe membership.