I meant it in the sense that I assume GP meant it, i.e., the index of an element in an ordered set is an integer corresponding to its position in that set, star

I meant it in the sense that I assume GP meant it, i.e., the index of an element in an ordered set is an integer corresponding to its position in that set, starting at 0 or 1 for the first element (depending on your indexing scheme of choice).