Inhibitors of polypolymerase, ways to make them and methods of treating patients using them are disclosed. Based on the control signal CS, a TS header processing section 16 specifies a TS header added to a payload of an I picture from the transport stream TS, and changes a value of a reserved bit in the TS header from 0 to 1. The hook portion and the receiving portion are formed in such a shape as to move the slide gears is a direction of canceling a rotational moment applied to the slide gears due to a backward load applied to the seat back when the cam member rotates in a lock canceling direction.