1. Synonyms for Coexists include accompanies, attends, coincides, concurs, synchronises, synchronizes, harmonises, harmonizes, coevolves and cohabits

2. If the actuator unit (180) switched off, a regulator expansion unit (600) estimates the actual phase and actual amplitude of a residual oscillation of the oscillator (190) and synchronises the harmonic desired value signal with the residual oscillation.