Can someone explain this sentence to me:

"Consider now the subsequences starting at the smallest natural number: inclusion of the upper bound would then force the latter to be unnatural by the time the sequence has shrunk to the empty one."

The previous statement asserts that inclusion of the lower bound is preferred because the sequence then starts with a natural number (so for a set 1<=x<12 the sequence starts at 1 instead of 1.000000 .... 1 in 1<x<12). How is inclusion of the upper bound forcing the "latter" (what is he referring to by latter) to be unnatural by the time the sequence has shrunk to the empty one.