We need some functions to find out what's inside a set, besides the "iterator". I think we need at least these, but I'd like if you would suggest more, and maybe better names:
->is_infinite_set ->is_empty_set ->is_closed_start ->is_closed_end More options (negative of the above): ->is_finite_set ->is_open_start ->is_open_end We already have: ->min ->max ->span ->duration ->iterator / ->next - Flavio S. Glock
