The integral symbol ∫ takes the shape of long English (s) letter. It is a mathematical operator that assigns to function in a way that can define the area, volume, displacement, and concepts that arise by joining infinitesimal. The German mathematician Gottfried Wilhelm Leibniz introduced the integral symbol by the end of the 17th century.

The shape of the Integral may be different from the known shape in the English language, which leans to the right. In German, and most of the central European languages it is upright. In the Russian language, it leans to the left, in German limits are placed above and below the symbol.