After the verb jña , when used in the sense of 'denying', the ātmanepada is used.,
The root jna which ordinarily means 'to know' and is parasmaipadi by rule 1.3.78, becomes Atmanepadi when through the virtue of any prefix it means 'to deceive:' as अपजानीते 'he deceives,' शतमपजानीते 'he denies the debt of a hundred rupees,' सहस्रमपजानीते 'denies a thousand.'
Why do we say when meaning \to deny ?\ Observe:- न त्वं किंचिदपि ज्ञानासि 'thou knowest not anything.',