The range(location-set) function returns returns a location set
containing one range for each location in the argument.
The range is the minimum range necessary to cover the entire location.
The range-inside(location-set) function
returns a location set containing the interiors of each of the locations in
the input.
The start-point(location-set)
function returns a location set that contains
one point representing the first point of each location in
the input location set.
For example,
start-point(//PERSON[1])
returns the point immediately before the first PERSON element.
start-point(//PERSON)
returns the set of points immediately before each PERSON element.
The end-point(location-set)
function acts the same as start-point() except that it returns the
points immediately after each location in its input.