Hiroshi Watanabe Koki Nishizawa Osamu Takaki A Coalgebraic Representation of Reduction by Cone of Influence. 177-194 2006 164 Electr. Notes Theor. Comput. Sci. 1 http://dx.doi.org/10.1016/j.entcs.2006.06.011 db/journals/entcs/entcs164.html#WatanabeNT06