1. A terminal device comprising:reception circuitry configured and/or programmed to receive a control channel including a downlink control information (DCI) format; and
transmission circuitry configured and/or programmed to transmit a physical uplink shared channel (PUSCH);
wherein, the DCI format including an uplink index and information for indicating a hybrid automatic repeat request (HARQ) process number,
in a case that both a first bit and a second bit of the uplink index are set to 1, the HARQ process number of the PUSCH corresponding to the first bit being X and the HARQ process number of the PUSCH corresponding to the second bit being mod (X+1, Z),
the mod (X+1, Z) being a function outputting a remainder when dividing (X+1) by Z,
the X being determined based on the information for indicating the HARQ process number, and
the Z being a value identical to a maximum number of HARQ processes in a serving cell determined by an uplink/downlink configuration.