Double summit eroded. Triple peaks occur more rarely - one example is the Rosengartenspitze in the Dolomites. The Illimani in Bolivia is an example of a quadruple summit. Well known double summits are (roughly from east to west): Double summit A double summit, double peak, twin summit or twin peak refers to a mountain or hill that has two summits, separated by a col or saddle. One well known double summit is Austria’s highest mountain, the Großglockner, where the main summit of the Großglockner is separated from that of the Kleinglockner by the Glocknerscharte col in the area of a geological fault.
Quadruple product Quadruple product In mathematics, the quadruple product is a product of four vectors in three-dimensional Euclidean space. The name "quadruple product" is used for two different products, the scalar-valued scalar quadruple product and the vector-valued vector quadruple product or vector product of four vectors . The scalar quadruple product is defined as the dot product of two cross products: where a, b, c, d are vectors in three-dimensional Euclidean space. It can be evaluated using the identity: or using the determinant: The vector quadruple product is defined as the cross product of two cross products: where a, b, c, d