Davide Bresolin Angelo Montanari Pietro Sala Guido Sciavicco A Tableau-Based System for Spatial Reasoning about Directional Relations. 123-137 2009 TABLEAUX http://dx.doi.org/10.1007/978-3-642-02716-1_10 conf/tableaux/2009 db/conf/tableaux/tableaux2009.html#BresolinMSS09