οὐκοῦν interrogative: not therefore? not then? (
οὐκοῦν . . . εὖ σοι δοκοῦσι βουλεύεσθαι; πρός γε ἃ ὁρῶσι
a. When a negative answer is expected we have οὐκοῦν οὐ (
b. οὐκοῦν and οὖν stand in parallel questions in
c. Some scholars write οὔκουν or οὐκ οὖν for οὐκοῦν interrogative (and inferential).
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].