Greg Lawler

@RP I think there are often reference to religious practices and concepts without mentioning the specific religion. For example, SEDER for a special meal without mentioning Judaism or NIRVANA without mentioning Buddhism. I do not thnk it is necessary to mention Catholicism here. I think it is much worse to use it as synonym for hell because then one is inaccurately describing the concept as understood by those who believe in it.

@Francis I am giving a lot of leeway to say that a least upper bound is a kind of end to a particular kind of set, a subset of the real line. Here the use of "end of the set" is in colloquial English and not in mathematical English and the answer is in mathematical language, but I think that is fair for a challenging puzzle. But even in this situation, the "upper bound" could be any number to the right of this set and does not connote the "end" point of the set.

@Francis As I said, I am giving leeway. For a particular class of sets, subsets of the real line, one often pictures them on the real axis which goes from -infinity to infinity in a left to right direction. If we drew a set on this line, then one could imagine (with leeway) the leftmost point (for the mathematically picky, the greatest lower bound) and the rightmost point (least upper bound) as "ends" of the set. Actually you write "end" point and, indeed, "endpoint" is a mathematical term for the leftmost and rightmost points of an interval in the real line.

@Barry Ancona It is analogous to cluing the word "ANIMAL" with the clue "TIGER". This would not be acceptable to most crossworders. Of course, "TIGER, e.g." would be acceptable clue for ANIMAL.