_{1}, ...,a

_{n}} find expressions e

_{1}, ...,e

_{n}such that {a

_{1}, ...,a

_{n}} = {e

_{1}, ...,e

_{n}}, and {e

_{i}} is a non-increasing sequence, where each expression is formed from the a

_{i}, the max function, and elementary arithmetic operations.

I will not post the answer to this problem, because I plan to publish it if it is not already known. If it is a known result, I would appreciate a reference.