See also: ∅-, -∅, -∅-, Ø [U+00D8 LATIN CAPITAL LETTER O WITH STROKE], [U+2300 DIAMETER SIGN], and ø [U+00F8 LATIN SMALL LETTER O WITH STROKE]

U+2205, ∅
EMPTY SET

[U+2204]
Mathematical Operators
[U+2206]

U+29B0, ⦰
REVERSED EMPTY SET

[U+29AF]
Miscellaneous Mathematical Symbols-B
[U+29B1]

Translingual edit

 
English Wikipedia has an article on:
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English Wikipedia has an article on:
Wikipedia
 
English Wikipedia has an article on:
Wikipedia

Etymology edit

The set-theoretic meaning of this symbol was introduced by the Bourbaki group in their treatise Éléments de mathématique. André Weil has said in his autobiography that he based it on the Norwegian letter Ø.[1]

Symbol edit

  1. (set theory) A set with no elements: the empty set.
    Synonyms: { }, {}
  2. (linguistic morphology) A null morpheme; a theoretical morpheme used in models of linguistic analysis to represent the absence of a morpheme where one might otherwise be expected.

See also edit

References edit

  1. ^ A. Weil, The Apprenticeship of a Mathematician, chapter V "Strasbourg and Bourbaki", p. 114; Birkhäuser Verlag 1992

Vietnamese edit

Etymology edit

From the empty set symbol.

Adjective edit

  1. Abbreviation of trống (empty).