Double lift small-time film "The Wonder of Magic", Dai Vernon said that he "may be the creator" of the double turnover, but wasn't certain. Double lift A double lift is a sleight of hand maneuver used by magicians in card magic. It is a method by which the identity of the top card may be kept secret by lifting the top two cards as one, making it seem as if only the top card is picked up. Similar techniques may be applied to more than two cards to perform a triple or even quadruple lift. The term was coined by Theo Annemann.
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