When Is Reachability Intrinsically Decidable?

A graph H is computable if there is a graph G = (V, E) isomorphic to H where the set V of vertices and the edge relation E are both computable. In this case G is called a computable copy of H. The reachability problem for H in G is, given u, w V , to decide whether there is a path from u to w. If the reachability problem for H is decidable in all computable copies of H then the problem is intrinsically decidable. This paper provides syntactic-logical characterizations of certain classes of graphs with intrinsically decidable reachability relations.

• Type: Conference
• Year: 2008
• Where: DLT
• Authors: Barbara F. Csima, Bakhadyr Khoussainov
• Keywords: Computable, Computable Copy, DLT 2008, Reachability Problem, Theoretical Computer Science