The input L is a differential operator. The output of this procedure is a linear differential operator  of minimal order such that for all solutions  of L, the determinant of the Wronskian  is a solution of .

An important property of the exterior power  is the following: If L has rational functions coefficients and L has a right-hand factor of order n, then M has a right-hand factor of order  (in other words:  has an exponential solution  where  is a rational function).

The argument domain describes the differential algebra. If this argument is the list , then the differential operators are notated with the symbols  and . They are viewed as elements of the differential algebra  where  is the field of constants.

If the argument domain is omitted then the differential specified by the environment variable _Envdiffopdomain is used. If this environment variable is not set then the argument domain may not be omitted.

Instead of a differential operator, the input can also be a linear homogeneous differential equation, eqn. In this case the third argument must be the dependent variable dvar.