Editing Tensor product (section)

=== Array programming languages ===
[[Array programming languages]] may have this pattern built in. For example, in [[APL programming language|APL]] the tensor product is expressed as <code>○.×</code> (for example <code>A ○.× B</code> or <code>A ○.× B ○.× C</code>). In [[J programming language|J]] the tensor product is the dyadic form of <code>*/</code> (for example <code>a */ b</code> or <code>a */ b */ c</code>).

J's treatment also allows the representation of some tensor fields, as <code>a</code> and <code>b</code> may be functions instead of constants. This product of two functions is a derived function, and if <code>a</code> and <code>b</code> are [[Differentiable function|differentiable]], then <code>a */ b</code> is differentiable.

However, these kinds of notation are not universally present in array languages. Other array languages may require explicit treatment of indices (for example, [[MATLAB]]), and/or may not support [[higher-order function]]s such as the [[Jacobian matrix and determinant|Jacobian derivative]] (for example, [[Fortran]]/APL).