Σ

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See also: σ, ς, , , Ʃ, σ., and σ'

Σ U+03A3, Σ
GREEK CAPITAL LETTER SIGMA
[unassigned: U+03A2]
Ρ
[U+03A1]
Greek and Coptic Τ
[U+03A4]

Translingual

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Symbol

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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

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(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

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  • (classification of formulae): Π, Δ

See also

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Ancient Greek

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Alternative forms

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Etymology

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From Phoenician 𐤔 (š, šīn).

Letter

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Σ (S) (uppercase, nonfinal lowercase σ, final lowercase ς)

  1. The letter sigma (σίγμα), the 18th letter of the ancient Greek alphabet.

Derived terms

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See also

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Greek

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Letter

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Σ (S) (uppercase, lowercase σ)

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

Numeral

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Σ (S)

  1. The number 200 in Greek numerals.

  1. The number 200,000 in Greek numerals.

See also

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see: Appendix:Greek alphabet