  A linear degenerate odd Poisson bracket (antibracket) realized solely on
Grassmann variables is presented. It is revealed that this bracket has at once
three nilpotent $\Delta$-like differential operators of the first, the second
and the third orders with respect to the Grassmann derivatives. It is shown
that these $\Delta$-like operators together with the Grassmann-odd nilpotent
Casimir function of this bracket form a finite-dimensional Lie superalgebra.
