Universit` a di Pisa Dipartimento di Informatica Technical Report: TR-06-05 DRedSOP: Synthesis of a new class of regular functions Anna Bernasconi, Department of Computer Science University of Pisa 56100 Pisa, Italy annab@di.unipi.it Valentina Ciriani, Department of Information Technologies University of Milano 26013 Crema (CR), Italy ciriani@dti.unimi.it May 29, 2006 ADDRESS: via F. Buonarroti 2, 56127 Pisa, Italy. TEL: +39 050 2212700 FAX: +39 050 2212726