Σ

See also: σ, ς, ∑, ⵉ, 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

Symbol

Σ

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

   $\sum _{n=1}^{3}n^{2}=1^{2}+2^{2}+3^{2}=14$

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

Ancient Greek

Alternative forms

• Ϲ (S)

Etymology

From Phoenician 𐤔 (š, “šīn”).

Letter

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

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

Derived terms

• (Cyrillic) С
• (Coptic) Ⲥ

See also

• (Greek-script letters) Α α, Β β, Γ γ, Δ δ, Ε ε, Ζ ζ, Η η, Θ θ, Ι ι, Κ κ, Λ λ, Μ μ, Ν ν, Ξ ξ, Ο ο, Π π, Ρ ρ, Σ σ ς, Τ τ, Υ υ, Φ φ, Χ χ, Ψ ψ, Ω ω
• (non-Classical letters) Ϝ (W) ϝ (w), Ͷ ͷ, Ͱ (H) ͱ (h), Ϻ (S) ϻ (s), Ϟ, ϟ, Ϙ (Q) ϙ (q), Ͳ (S) ͳ (s)
• (punctuation) · ;
• (diacritics) ᾿ ῾ ◌́ ◌̀ ῀ ¨

Symbol

Σ • (S)

1. A counter for staters. An abbreviation of στατήρ (statḗr). Used as a tally mark, as in ΣΣΣΣ (4 staters) and Τ𐅐𐅏ΣΣΣ (1 talent 18 staters).

Derived terms

• 𐅏 (5 staters)
• 𐅐 (10 staters)
• 𐅑 (50 staters)
• 𐅒 (100 staters)
• 𐅓 (500 staters)
• 𐅔 (1,000 staters)
• 𐅕 (10,000 staters)
• 𐅖 (50,000 staters)

Greek

Letter

Σ • (S) (uppercase, lowercase σ)

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

Numeral

Σ • (S)

1. The number 200 in Greek numerals.

,Σ

1. The number 200,000 in Greek numerals.

See also

see: Appendix:Greek alphabet