The Tree Evaluation Problem : Towards Separating P from NL Lecture # 6 : 26 February 2014

As of today, we do not know if even one among the above sequence of containments is strict. In fact, it is open if AC(6)=PH ! In this lecture by Steve we learn about an attempt aimed at separating P from NL using a specific problem called the Tree Evaluation Problem. Most of the contents of the talk are derived from the work “Pebbles and Branching Programs for tree evaluation” [1] by Steve Cook, Pierre McKenzie, Dustin Wehr, Mark Braverman and Rahul Santhanam. The problem chosen in this program is inspired by Michael Taitslin’s FOCS 2005 submission, an attempt to separate NL and P.