A series expansion is a representation of a particular function as a sum of powers in one of its variables, or by a sum
of powers of another (usually elementary) function f(x).
An asymptotic series is a series expansion of a function in a variable x which may converge or diverge (Erdélyi 1987,
p. 1), but whose partial sums can be made an arbitrarily good approximation to a given function for large enough x.
Asymptotic series can be computed by doing the change of variable x -> 1/x and doing a series expansion about
zero. Many mathematical operations can be performed on asymptotic series. For example, asymptotic series can be
added, subtracted, multiplied, divided (as long as the constant term of the divisor is nonzero), and exponentiated,
and the results are also asymptotic series (Gradshteyn and Ryzhik 2000, p. 20).