[boost] [Math/nextafter] A question of naming functions...

Folks I'm looking for some good names for some functions I'm on the brink of adding to Boost.Math (all in namespace boost::math::): T nextafter(T val, T dir) Returns the next representable floating point value to "val" in the direction of "dir". This name is basically fixed, since it's the one that C99 uses. T next_greater(T val) Returns the next representable value greater than "val". T next_less(T val) Returns the next representable value less than "val". T edit_distance(T a, T b) Returns the number of floating point representations between values a and b. So the questions are: can you think of any better names, or are these OK? And should edit_distance return a signed or absolute value? Thanks in advance, John.