The 511 Davida Array Transform, denoted as \mathfrak{D_{511}}, is a transform that can be applied to multivariable functions and finite arrays according to four rules: Base Iteration, Self Iteration, Dimensional Iteration, and Variadic Iteration. Base Iteration states that \mathfrak{D_{511}}[f,n] is the function f composed with itself n times, with each composition using the function f in place of each variable in the function. Self Iteration states that evaluating an array with the 511 Davida Array Transform involves applying the transform to the last element of the array, indicating the number of times that the transform is applied to itself. Dimensional Iteration involves the use of the shorthand notation ((a)/_b) to indicate that the transform should be applied to arrays of length b. Finally, Variadic Iteration states that the function should be replaced with a new function formed by applying the 511 Davida Array Transform t times to the function, where each application of the transform to the function results in a function whose variables include the variables of all previous stages of the transform applied to the function.
Arrays are allowed instead of f as well! As long as it can act as a function (input -> output), it is allowed.