Is an Arhat's Entry into Nirvāṇa Equivalent to Entering the Tathāgatagarbha?

The arhat's seven consciousnesses and five aggregates are entirely generated and sustained by the tathāgatagarbha; there has never been a single instant when they could exist independently apart from the tathāgatagarbha. Therefore, the arhat has never been outside the tathāgatagarbha, much less can he enter it; otherwise, the arhat would also be a dharma-essence that is unborn and unceasing, existing originally without cause or condition, and would be equivalent to the tathāgatagarbha. Thus, when an arhat enters nirvāṇa, it does not mean entering the tathāgatagarbha.

Nirvāṇa is a state in which the tathāgatagarbha exists alone, without the seven consciousnesses and five aggregates. Although in this state there is only the tathāgatagarbha and no other dharmas, it is still a state of the tathāgatagarbha abiding alone, not conjoined with the seven consciousnesses and five aggregates. If nirvāṇa refers to such qualities as being unborn and unceasing, neither increasing nor decreasing, pure and undefiled, and so on, then the tathāgatagarbha possesses the nature of nirvāṇa. But the tathāgatagarbha is not identical to nirvāṇa, because the tathāgatagarbha also has many other qualities and other states; nirvāṇa is not entirely equivalent to the tathāgatagarbha. The tathāgatagarbha is the essence, while nirvāṇa is the quality and state of that essence.