====== Kathryn Nyman (Cornell University) ======

====== Incidence Numbers for Line and Pseudo-line Arrangements ======

===== Abstract for the Combinatorics and Number Theory and Algebra Seminars 2001 January 30 =====

Given //n// points in the plane, how many lines are determined? And how many point-line incidences? We look at this question by counting the flag Whitney numbers of geometric lattices of rank 3.