Provided are compounds of Formula I:or a pharmaceutically acceptable salt thereof, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, X and m are as defined herein. The semiconductor integrated circuit includes a memory functional block with a variable storage capacity, a functional block, and a terminal group for testing. The receiver is adapted to cooperate with a portion of a structural member of the trailer when installed. The gate pulses have different voltages andor widths. The method provides the advantage of an improved binaural noise reduction compared to the state of the art with small or less signal distortion. Available air pressure is monitored and a clutch interlock implemented through the vehicle electrical control system is made responsive thereto to prevent engagement of the clutch if the load is too heavy for the available air pressure.