The simplest way to define a powerset of S without the empty set?

Hi all,

In the VRP, I have to define a set N ={1,2,…,n} customer and a set S of all subsets of N. S do not include the empty set.

My Problem is how to defined S without the empty set in the simplest way?

I presume to define as follows, however, it is not beautiful and too long
 

int n  = ...;
{int} N= asSet(1..n) ;
{} empty = {};

range r=1.. ftoi(pow(2,card(customer)));
{int} S [k in r] = {i | i in s: ((k div (ftoi(pow(2,(ord(s,i))))) mod 2) == 1)} diff empty;