Satisfiability and Model Checking for the Logic of Sub-Intervals under the Homogeneity Assumption

The expressive power of interval temporal logics (ITLs) makes them really fascinating, and one of the most natural choices as specification and planning language. However, for a long time, due to their high computational complexity, they were considered not suitable for practical purposes. The recent discovery of several computationally well-behaved ITLs has finally changed the scenario. In this paper, we investigate the finite satisfiability and model checking problems for the ITL D featuring the sub-interval relation, under the homogeneity assumption (that constrains a proposition letter to hold over an interval if and only if it holds over all its points). First we prove that the satisfiability problem for D, over finite linear orders, is PSPACE-complete; then we show that its model checking problem, over finite Kripke structures, is PSPACE-complete as well. The paper enrich the set of tractable interval temporal logics with a meaningful representative.