They are the same set. Rearranging the elements in a different order between the braces does not change the set. All of the following represent exactly the same set: {a, c, m, e} {a, c, e, m} {a, m, c, e} {a, m, e, c} {a, e, c, m} {a, e, m, c} {c, a, m, e} {c, a, e, m} {c, m, a, e} {c, m, e, a} {c, e, a, m} {c, e, m, a} {m, a, c, e} {m, a, e, c} {m, c, a, e} {m, c, e, a} {m, e, a, c} {m, e, c, a} {e, a, c, m} {e, a, m, c} {e, c, a, m} {e, c, m, a} {e, m, a, c} {e, m, c, a} Edwin