The third (and the highest) type of Yāvatkathika Anaśana (fasting-unto-death);
it is also called Prāyopagamana (Anaśana), in which the undertaker of the Anaśana renounces the intake of all the four kinds of aliment and keeps his body completely motionless in lying down posture like a (cut branch of) tree.
pādasyevopagamanam-aspandatayā'vasthānaṃ pādapopagamanam, idaṃ ca caturvidhāhāraparihāraniṣpannameva bhavati.
(AupaVṛ 71)
See - Prāyopagamana Anaśana.