### EtymologyEdit

Gottfried Leibniz based the symbol on the Latin word *summa* (“sum”), which he wrote **ſ**umma (with a long s 'ſ' ). This use first appeared publicly in his paper *De Geometria*, published in *Acta Eruditorum* of June, 1686,^{[1]} but he had been using it in private manuscripts since at least 1675.^{[2]}

**∫**

- (mathematics) Denotes the integral

#### Related termsEdit

#### ReferencesEdit

- ^
*Mathematics and its History*, John Stillwell, Springer 1989, p. 110
- ^
*Early Mathematical Manuscripts of Leibniz*, J. M. Child, Open Court Publishing Co., 1920, pp. 73–74, 80.