Employee-related costs and benefits in IT investment decisions: an empirical investigation

Abstract. We present algorithms for computing similar- ity relations of labeled graphs. Similarity relations have applications for the refinement and verification of reac- tive systems. For finite graphs, we present an O(mn) al- gorithm for computing the similarity relation of a graph with n vertices and m edges (assuming m 2 n). For ef- fectively presented infinite graphs, we present a symbolic similarity-checking procedure that terminates if a finite similarity relation exists. We show that 2D rectangular automata, which model discrete reactive systems with con- tinuous environments, define effectively presented infinite graphs with finite similarity relations. It follows that the refinement problem and the VCTL’ model-checking prob- lem are decidable for 2D rectangular automata. 1 Introduction A labeled graph G = (V, E, A, ((.))) consist of a (pos- sibly infinite) set V of vertices, a set E C V2 of edges, a set A of labels, and a function ((a)): V --f A that maps each vertex