 Since then fusion has been a much worked theme. Important results are the applications of fusion to simulations and to the question of transfer of properties among modal logics. Simulations make the strength of normal monomodal logics explicit, as they can, in a sense, simulate all modal logics (see Kracht and Wolter 1999). With respect to transfers, the preservation of properties such as completeness, finite modal property, decidability and interpolation by fusion of modal logics was extensively studied in Fine and Schurz 1996. More general and deeper results in the same spirit were obtained in Kracht and Wolter 1991, and a survey of most of those results can be found in Kracht and Wolter 1997. These results show the robustness of fusion as a combination method within the scope of modal logics, for fulfilling the requirement of preserving the properties of the logics being combined.