Counting for rigidity under projective transformations in the plane

Leah Wrenn Berman, Signe Lundqvist, Bernd Schulze +4

Let $P$ be a set of points and $L$ a set of lines in the (extended) Euclidean plane, and $I\subseteq P\times L$, where $i=(p,l)\in I$ means that point $p$ and line $l$ are incid…