  We show that if $\mu$ is an invariant measure for the long range exclusion
process putting no mass on the full configuration, $L$ is the formal generator
of that process and $f$ is a cylinder function, then $Lf\in\mathbf{L}^1(d\mu)$
and $\int Lf d\mu=0$. This result is then applied to determine (i) the set of
invariant and translation-invariant measures of the long range exclusion
process on $\mathbb{Z}^d$ when the underlying random walk is irreducible; (ii)
the set of invariant measures of the long range exclusion process on
$\mathbb{Z}$ when the underlying random walk is irreducible and either has zero
mean or allows jumps only to the nearest-neighbors.
