To the extent that one's battling still (2,2,3)
I believe the answer is:
in so far
'to' is the definition.
Both the definition and answer are adverbs.
Maybe you can see a link between them that I don't see?
'extent that one's battling still' is the wordplay.
I cannot quite understand how this works, but
'still' could be 'sofar' (I've seen this in another clue) and 'sofar' is found within the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'the' acts as a link.
Can you help me to learn more?
(Other definitions for in so far that I've seen before include "Inasmuch" , "To the degree or extent that" .)