Σ

Unicode name	GREEK CAPITAL LETTER SIGMA
Unicode block	Greek and Coptic
Codepoint	U+03A3
Ρ ← Greek and Coptic → Τ

See also: ∑ [U+2211 N-ARY SUMMATION], Ʃ [U+01A9 LATIN CAPITAL LETTER ESH], and ⵉ [U+2D49 TIFINAGH LETTER YI]

Translingual

Symbol

Σ

1. (mathematics) Σ. Sum over a set of like terms:

   $\sum_{n=1}^2 n^2 = 1 + 4 = 5$

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

• Σ on Wikipedia.Wikipedia

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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.

,Σ

1. The number 200,000 in Greek numerals.