  Recently Kaniel & Itin proposed a gravitational model with the wave type
equation [\square+\lambda(x)]\vartheta^\alpha=0 as vacuum field equation, where
\vartheta^\alpha denotes the coframe of spacetime. They found that the viable
Yilmaz-Rosen metric is an exact solution of the tracefree part of their field
equation. This model belongs to the teleparallelism class of gravitational
gauge theories. Of decisive importance for the evaluation of the Kaniel-Itin
model is the question whether the variation of the coframe commutes with the
Hodge star. We find a master formula for this commutator and rectify some
corresponding mistakes in the literature. Then we turn to a detailed discussion
of the Kaniel-Itin model.
