I want to know the answer to the following question:
How many ways does the Prabhakara subschool of Mimamsa say there are to gain knowledge?
All the background I'm provided with is that "The Kumārila Bhaṭṭa sub-school of Mīmāṃsā added sixth to its canon of reliable epistemology - anupalabdi (non-perception, negative/cognitive proof).". Is that enough to answer the question?
Answer: no