  We study subsolutions of the Dirac and Duffin-Kemmer-Petiau equations
described in our earlier papers. It is shown that subsolutions of the
Duffin-Kemmer-Petiau equations and those of the Dirac equation obey the same
Dirac equation with some built-in projection operator. This covariant equation
can be referred to as supersymmetric since it has bosonic as well as fermionic
degrees of freedom.
