Agostino Dovier Eugenio G. Omodeo Enrico Pontelli Gianfranco Rossi A Language for Programming in Logic with Finite Sets. 1-44 1996 28 J. Log. Program. 1 db/journals/jlp/jlp28.html#DovierOPR96 http://dx.doi.org/10.1016/0743-1066(95)00147-6