I am working on a simple PDE and am trying to find the values of the constant coefficients in the PDE such that a function of a particular form satisfies the equation. The function is a sum of general functions of x, y and z in the argument: for example, one of them is $f(x-2y+z)$. I then have a PDE with constant coefficients which contains a sum of some mixed and some single second partial derivatives of that function with constant coefficients in front of some of the derivatives. Is there any relatively easy package with Maple which would enable me to find the values of those coefficients such that the function of the form I have will satisfy the PDE? I can provide more exact details of the PDE if necessary but didn't want to get bogged down in details as interested in the principle.