The present invention provides a polymerization process utilizing a dual ansa-metallocene catalyst system. The optical member moves to a position where the optical path of the optical image of the subject, which is incident via the first lens group, is changed to the direction of the second lens group when a picture is to be taken, and moves to a position where it is withdrawn from this area when a picture is not to be taken. The transformation module may also transform hierarchical data into binary data for transmission on a network. A slider having such teeth 13 of a comb will prevent a drastic change in a contact state such as instantaneous disconnection between the tip of the teeth 13 of a comb of the slider and a surface to be slid on from occurring, so that generation of noise in signals flowing through the slider and deterioration in resistance properties of the slider are prevented.