(śyena altar scheme)
Rāmānujācārya depicts Kumārila's position about arthabhāvanā as follows:
The arthabhāvanā ("bringing about" force) is a human effort, his undertaking of an activity (arthabhāvanā puruṣaprayatnas tatpravṛttir iti yāvat).
If Rāmānujācārya's interpretation of Kumārila is right (as I am inclined to think), then Kumārila, against Nyāya, does not differentiate between an effort and its concrete realisation. Consequently, Mīmāṃsakas (see, again, Rāmānujācārya's Tantrarahasya) count cognition (jñāna), desire (icchā) and effort (prayatna) as a complete sequence, whereas Nyāya texts usually add 'action' at the end. The non-separation of effort and action puts the whole burden of action in the moment of its initiation (called pra-vṛtti) and is IMHO linked to the Mīmāṃsā lack of interest for the actual performance of sacrifices. Enough, maintain Mīmāṃsakas, that the sacrifice is enjoined (even the avoidance to perform what has been enjoined does not alter the state of affairs of its having been enjoined).
But later authors, even Mīmāṃsaka ones, segment again arthabhāvanā into vyāpāra and prayatna, thus annihilating the idea that the actual performance of an action is not relevant to its status.
(I am grateful to Hugo David for having made me reflect about Khaṇḍadeva and Mādhava).