Double Klondike Double Klondike Double Klondike is a variant on the playing card game popularly known either as Solitaire or Snap-Up Patience, specifically a variant on the most well-known version of the game, Klondike. It is sometimes referred to simply as "Double Solitaire". Triple Solitaire, Quadruple Solitaire, etc. is also possible and is played. It is not to be confused with the single-player game of Gargantua which is also known as Double Klondike. As the name suggests, Double Klondike is a two-player game, and is played with two full packs of playing cards, minus the Jokers; for the purpose of Double Klondike,
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