Affiliation: | 1.Department of Computer Sciences, University of Verona, Str. Le Grazie 15, 37134, Verona, Italy ;2.Department of Mathematics and Computer Science, University of Ferrara, Via Machiavelli 35, 44121, Ferrara, Italy ;3.Department of Mathematical Sciences, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino, Italy ; |