The present invention relates to a composite user agent acting on behalf of a group of member user agents in a communication network. The system comprises a ballast with a resonant circuit having a resonant frequency for supplying power to the discharge lamp and a heating power to each filament of the discharge lamp. According to the invention, such an envelope is obtained by using a hot gas that is preaccelerated to such a degree that the central gas jet is preferably without pulse losses. Further, an intermediate result of the floating point computation is analyzed to determine whether it is inexact. The present invention is further directed to processes for the preparation of intermediates in the synthesis of the benzo-fused heteroaryl derivatives. In a fifth embodiment of the invention, additional copper features are placed on the substrate to be polished.