A belt-type door opening and closing drive apparatus is provided, which can reduce the noise and dimensions thereof and make full use of the mechanical safety function in the event of an accident. The anchored mount has an inner tubular wall defining an insert opening and having an inserting route, a seat, and a rest wall. Control functions of each switch may also be organized into a control plane. During the second stage the timing recovery system of the master is trained in both frequency and phase, the equalizer of the master is trained and the noise reduction system of the slave is trained. The compounds are useful for treating disorders in which HIV and genetically related viruses are implicated. In accordance with the present invention, an invocation of a shares operation that specifies a first event and a second event is received.