then rotating {TAIL ~ the rotor} by selectively exciting the coils while the tooth magnetization remains to produce {HEAD ~ a magnetic rotational force} on the rotor; and 
then rotating { TAIL ~ the rotor } by selectively exciting the coils while the tooth magnetization remains to produce { HEAD ~ a magnetic rotational force } on the rotor ; and
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH