The diameter of an undirected graph is the minimal number d such that there is a path between any two vertices of the graph of length at most d. The radius of a graph is the minim...
Edith Hemaspaandra, Lane A. Hemaspaandra, Till Tan...
Deciding whether a finite set of polyominoes tiles the plane is undecidable by reduction from the Domino problem. In this paper, we prove that the problem remains undecidable if t...
We study the boundedness problem for monadic least fixed points as a decision problem. While this problem is known to be undecidable in general and even for syntactically very res...
: In this paper we deal with the arc ranking problem of directed graphs. We give some classes of graphs for which the arc ranking problem is polynomially solvable. We prove that de...
We study the problem of answering queries over sources with limited access patterns. Given a first-order query Q, the problem is to decide whether there is an equivalent query whi...