In the context of the MRAC approach this single function represents an important building block and device within many functions in this collection. It is, intrinsically, a most powerful yet simple concept.
In essence, the function enables items in a new-element of elements to be directly substituted for items a old-element of elements. In the example below, for example, element 1/16 is associated with and substituted for 0, element -1/16 is associated with and substituted for 1, and so on.