We investigate the s-t-connectivity problem for directed planar graphs, which is hard for L and is contained in NL but is not known to be complete. We show that this problem is log...
We study the complexity of restricted versions of s-t-connectivity, which is the standard complete problem for NL. In particular, we focus on different classes of planar graphs, o...
Eric Allender, David A. Mix Barrington, Tanmoy Cha...
Graph-structured databases and related problems such as reachability query processing have been increasingly relevant to many applications such as XML databases, biological databas...
We make progress in understanding the complexity of the graph reachability problem in the context of unambiguous logarithmic space computation; a restricted form of nondeterminism....
Chris Bourke, Raghunath Tewari, N. V. Vinodchandra...
Abstract. We survey classical and selected recent work on the reachability problem over finitely presented infinite graphs. The problem has a history of 100 years, and it is centra...