{1, 2 ,3} = {1, 2, 3, 3, III}?
{1, 2 ,3} = {one, dos, three}?
{Tom, Dick, Harry} = {Thomas, Richard, Harrison}?
Seems to me, these are undetermined until the set's "type" or "category" definition of its members is defined so as to determine what elements are members of the set... whether...