An arched strut net featuring ℓ= 13 closed loops, which avoids an semi-circular arch obstacle (p = 1), is reduced to an open strut net (ℓ= 0) by employing the loop reduction procedure presented in [13]. The active and reactive external forces are at the vertices of a convex polygon (q = 0) and the obstacle intersects this polygon (p0 = 1). It is worth observing that the final arch satisfies ℓ≤ q + p − p0, in agreement with Theorem 1 of Section 2.