Empty Set
Part of Math Symbols
Empty Set has no standard Windows Alt code. Copy the character directly, or use its HTML entity or Unicode value instead.
- Alt code
- None
- HTML entity
- ∅
- Unicode
- U+2205
About this symbol
The empty set sign, for a set with nothing in it, was introduced in 1939 by the French mathematician André Weil, one of the group who wrote together under the name Nicolas Bourbaki. Weil said he took it from the Norwegian letter Ø.
It looks like the diameter sign ⌀ and the letter ø, but all three are separate characters.
Unicode facts
- Official name
- EMPTY SET
- Also called
- Null set
- Type
- Maths symbol
- Unicode block
- Mathematical Operators
- Unicode group
- Miscellaneous mathematical symbols
- Added in
- Unicode 1.1 (1993)
- Unicode notes
- Used in linguistics to indicate a null morpheme or phonological “zero”
Click the symbol or any value at the top of the page to copy it. See the full Math Symbols chart for related characters.