Emergent semantics and cooperation in multi−knowledge environments: The ESTEEM architecture por Aiello, C, Roberto�Baldoni, Bonomi, D, Castano, S, Catarci, T, Curino, C, de Antonellis, V, Ferrara, A, Melchiori, M, Milano, D, Orsi, S, Poggi, A, Leonardo�Querzoni, Quintarelli, E, Rossato, R, Salvi, D, Scannapieco, M, Schreiber, F, Tanca, L, Pergiovanni, S