that the triangle groups (2, 4, 5) and (2, 5, 5) are not systolic. Along the way we prove some
results about subsets of systolic complexes stable under involutions. … In the present paper
we close this gap and prove that the two hyperbolic triangle groups (2, 4, 5) and (2, 5, 5) are
also not systolic. In hindsight this shows that the systolization procedure of [7] was best
possible within the class of …