 Integrals of such expressions can occasionally be solved in terms of the gamma function when no elementary solution exists.For example, if is a power function and is a linear function, a simple change of variables gives the evaluation

The fact that the integration is performed along the entire positive real line might signify that the gamma function describes the cumulation of a time-dependent process that continues indefinitely, or the value might be the total of a distribution in an infinite space.It is of course frequently useful to take limits of integration other than 0 and to describe the cumulation of a finite process, in which case the ordinary gamma function is no longer a solution; the solution is then called an incomplete gamma function.