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Definition 2024


Σ

Σ


Σ U+03A3, Σ
GREEK CAPITAL LETTER SIGMA
[unassigned: U+03A2]
Ρ
[U+03A1]
Greek and Coptic Τ
[U+03A4]
See also: σ, ς, , , Ʃ, σ., and σ'

Translingual

Symbol

Σ

  1. (mathematics) Σ. Sum over a set of like terms:
  2. (topology) suspension or reduced suspension
  3. (mathematics) A class (in the arithmetical hierarchy) of formulae whose outermost unbounded quantifiers are existential quantifiers

Usage notes

(mathematics): Though there exists a distinct symbol () for the purpose of the mathematical summation, the upper case sigma here is often used for convenience.

Coordinate terms

  • (classification of formulae): Π, Δ

See also


Greek

Letter

Σ (S) (uppercase, lowercase σ)

  1. The upper case letter sigma (σίγμα), the 18th letter of the modern Greek alphabet.

See also

see: Appendix:Greek alphabet

Numeral

Σ (S)

  1. The number 200 in Greek numerals.

  1. The number 200,000 in Greek numerals.

σ

σ


σ U+03C3, σ
GREEK SMALL LETTER SIGMA
ς
[U+03C2]
Greek and Coptic τ
[U+03C4]
See also: ς, Σ, σ., and σ'

Translingual

Symbol

σ

  1. (mathematics, statistics) Standard deviation.
  2. (mathematics) Sum of divisors.
  3. (linguistics, phonology) Syllable.
  4. (spatial databases) The select operation.

Greek

Letter

σ, ς (Σ uppercase)

  1. The lower case letter sigma (σίγμα), the 18th letter of the modern Greek alphabet. When the final letter in a word of lower case letters is sigma the alternative (ς) form must be used; it may be used only in this final position.

Numeral

σ'

  1. The number 200 in Greek numerals.

  1. The number 200,000 in Greek numerals.

See also