1. DEI, Polytechnic University of Bari, Italy. E-mails: vitowalter.anelli@poliba.it, tommaso.dinoia@poliba.it, jessica.rosati@poliba.it
2. School of Science and Technology, University of Camerino, Italy. E-mails: renato.deleone@unicam.it, jessica.rosati@unicam.it
3. Department of Computer Science, University of Oxford, UK. E-mail: thomas.lukasiewicz@cs.ox.ac.uk