  Given a simple polygon $\cal P$, in the Art Gallery problem, the goal is to
find the minimum number of guards needed to cover the entire $\cal P$, where a
guard is a point and can see another point $q$ when $\overline{pq}$ does not
cross the edges of $\cal P$.
  This paper studies a variant of the Art Gallery problem in which the
boundaries of $\cal P$ are replaced by single specular-reflection edges,
allowing the view rays to reflect once per collision with an edge. This
property allows the guards to see through the reflections, thereby viewing a
larger portion of the polygon.
  For this problem, the position of the guards in $\cal P$ can be determined
with our proposed $\mathcal{O}(\log n)$-approximation algorithm. Besides
presenting an algorithm with the mentioned approximation factor, we will see
that reflection can decrease the number of guards in practice. The proposed
algorithm converts the generalized problem to the Set Cover problem.
