param appell1 c array param; array c; appell1 returns an annihilating ideal for the Lauricella function F_D(a,b_1, ..., b_n,c; x_1,...,x_n) for the parameter << param >> = [a, c, b_1, ..., b_n]. In case of n=2, the function is called the Appell function F_1. c = [ generators, variables ] Note that for a special set of parameters, the returned differential equation is not holonomic, e.g., [[1 2 3 4]] appell1 rank :: This happens because we do not included the Euler-Darboux operators in the return value of appell1. It will be included in a future. Example: [ [1 -4 -2 5 6] ] appell1 rank :: For details, see P.Appell et Kampe de Feriet, Fonction hypergeometrique et hyperspheriques -- polynomes d'Hermite, Gauthier-Villars, 1926.