Fabio Alessi Franco Barbanera Mariangiola Dezani-Ciancaglini Intersection Types and Computational Rules. 2003 84 Electr. Notes Theor. Comput. Sci. http://www1.elsevier.com/gej-ng/31/29/23/142/23/show/Products/notes/index.htt#007 db/journals/entcs/entcs84.html#AlessiBD03