U+2205 "∅" Empty Set Unicode Character
Unicode Version 17.0
∅
U+2205 "∅" Empty Set is a mathematical symbol that represents the unique set containing no elements, commonly known as the empty set or null set. It was introduced to mathematics by André Weil and is widely used in set theory, logic, and various branches of mathematics to denote nothingness or a void collection. This symbol is distinct from the similar-looking Greek letter phi (Φ or φ) and has been encoded in Unicode since version 1.1 in 1993. In addition to its mathematical significance, the empty set symbol is sometimes used in other fields such as computer science, linguistics, and engineering to indicate an absence of values or a state of no information.
General Properties
| Code Point | U+2205 |
| Version Added | 1.1 |
| Name | Empty Set |
| Block | Mathematical Operators |
| General Category | Math Symbol |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Other Neutral |
Encodings
| HTML Decimal Encoding | ∅ |
| HTML Hex Encoding | ∅ |
| UTF-8 Encoding | 0xE2 0x88 0x85 |
| UTF-16 Encoding | 0x2205 |
| UTF-32 Encoding | 0x00002205 |
| C/C++/Java Escape | \u2205 |
Unicode Properties
| NFC Quick Check | Yes |
| NFD Quick Check | Yes |
| NFKC Quick Check | Yes |
| NFKD Quick Check | Yes |
| Numeric Type | None |
| Numeric Value | NaN |
| Line Break | Alphabetic |
| Script | Common |
| Script Extensions | Common |
| Indic Syllabic Category | Other |
| Pattern Syntax | Yes |
| Math | Yes |
| Vertical Orientation | Rotated |
| Grapheme Base | Yes |
| Grapheme Cluster Break | Other |
| Word Break | Other |
| Sentence Break | Other |