  We show that the BV (Batalin Vilkovisky) action, formulated with an extended
BRST symmetry (including the shift symmetry), is also invariant under an
extended anti-BRST transformation (where the antifields are the parameters of
the transformation), when the gauge fixing Lagrangian is both BRST and
anti-BRST invariant. We show that for a general gauge fixing Lagrangian, the BV
action can be written in a manifestly extended BRST invariant manner in a
superspace with one Grassmann coordinate whereas it can be expressed in a
manifestly extended BRST and anti-BRST invariant manner in a superspace with
two Grassmann coordinates when the gauge fixing Lagrangian is invariant under
both BRST and anti-BRST transformations.
