173 k-Fold Product

A Cartesian product of k copies of one set that is used as the domain of a multilinear mapping of k inputs.

definition (k-Fold Product) A set constructed by the Cartesian product of \(k\) copies of a single set, \(X^k\), where the following condition applies:

  • The resulting set consists of all ordered \(k\)-tuples where

  • each coordinate is an element of the original set.

where

  • \(k\) is a positive integer representing the number of repetitions.
  • \(X\) is the underlying set.
  • \(X^k\) denotes the \(k\)-fold Cartesian product \(X \times \dots \times X\).

Note:

  • \(X\) may be a topological space.
  • \(X\) may be a vector space.
  • \(X^k\) is also written \(V^k\).

173.1 Elementary Example

173.1.1 Simple

The \(2\)-fold product is the Cartesian product of two copies of one set.

\[ V = \{ a,\ b,\ c \} \]

\[ V^{2} = V \times V \]

\[ (a,b),\ (b,a),\ (a,c) \in V^{2} \]

where

  • \(V^{2}\) is the \(2\)-fold product.
  • \(k = 2\) is the number of factors.