In that case it would at least be interesting to know if there are any counterexamples.

@Vectornaut (or Alexey) Could either of you forward it to me as well?

Are there any resources in English on Brückner's 1906 polyhedra?

Igor, do you have any texts to recommend for the subject of general elliptic operators.

I phrased it poorly. When I say that f is left monogenic such that the sum is zero, what I really meant is that left monogenic functions are functions such that the sum of the e_j partial_j is always 0, which the function f is assumed to be (sim. right monogenic and g).

@Lierre , My current work is in math bio, but I also have an interest in operator theory.