When applied to a ``measure'' function f, the call increasing f returns a
binary function ordering elements in a call increasing f x y by
f(y) , where the ordering is the OCaml polymorphic ordering.
FAILURE CONDITIONS
Never fails unless the measure function does.
EXAMPLE
# let nums = -5 -- 5;;
val nums : int list = [-5; -4; -3; -2; -1; 0; 1; 2; 3; 4; 5]
# sort (decreasing abs) nums;;
val it : int list = [5; -5; 4; -4; 3; -3; 2; -2; 1; -1; 0]