If it helps, my rationale for giving primacy to the lower-bound is because the only common use-case I've come across with overlapping bounds is with time periods. e.g. Accumulated rainfall over hours: 0-to-3, 0-to-6, 0-to-12, 6-to-9, 6-to-12, 6-to18, etc. In which case ordering by lower bound, then upper bound, then point fits with usage as I've seen it.