Complement Symbol
∁ is the complement symbol, commonly used in math and logic to denote what is outside a set or statement.
U+2201
The symbol ∁ (Unicode U+2201) is known as the complement sign. It’s widely used in mathematics and related logic notations. This page helps you understand its meaning and copy it reliably in text and code.
Complement Symbol Meaning
The complement symbol ∁ represents “complement” in set and logic contexts. In set notation, it typically means “the elements not in a given set,” often written informally as everything outside the set. In logic or Boolean-style notation, it can be used to express the opposite of a condition, similar in spirit to negation depending on the surrounding notation. Because complement is context-dependent, it’s important to read ∁ alongside the set or proposition it applies to. In documents, it can also help visually distinguish “not A” or “everything else” from other operators.
Common uses
- •Writing set theory expressions like “not in A” using ∁A
- •Denoting logical complements (opposite conditions) in logic notes
- •Labeling diagrams or Venn regions that represent “outside” a set
- •Clarifying negation in plain-language mathematical writing or tutoring
- •Formatting algebra/logic content where a distinct complement operator is preferred
Examples
∁ Complement Symbol (U+2201)
- ∁∁A is the complement of set A.
- ∁If x ∈ A, then x ∉ ∁A.
- ∁The region outside B can be written as ∁B.
- ∁We analyze the complement case: ∁P.
- ∁Take elements that are not in S: ∁S.
Variations
Ready to copy
Technical codes
| Unicode | U+2201 | |
| HTML Entity | ∁ | |
| HTML Code | ∁ | |
| CSS | \2201 |
FAQ
What does the symbol ∁ mean?
∁ is the complement symbol (Unicode name: COMPLMENT). It commonly denotes the complement of a set or the opposite of a condition, depending on context.
Is ∁ the same as negation?
It’s similar in meaning to “not” in many logical contexts, but the exact interpretation depends on how the symbol is used with the expression it complements.
How can I copy ∁ into HTML?
Use the HTML entity: ∁.
How do I include ∁ in CSS or JavaScript?
CSS escape: \\2201. JavaScript escape: \\u{2201}.