This is an addition to a series of papers [FL1, FL2, FL3, FL4], where we
develop quaternionic analysis from the point of view of representation theory
of the conformal Lie group and its Lie algebra. In this paper we develop split
quaternionic analogues of certain results from [FL4]. Thus we introduce a space
of functions Dh⊕Da with a natural action of the Lie
algebra gl(2,HC)≃sl(4,C), decompose Dh⊕Da into irreducible components and
find the gl(2,HC)-equivariant projectors onto
each of these irreducible components.Comment: 10 pages, 4 figures, accepted for publication in the "Proceedings of
the 30th International Colloquium on Group Theoretical Methods", to be
published as a volume of Journal of Physics: Conference Proceeding