In which type of inference is the middle term both positively and negatively related to the major term, as per the classical Indian school of logic?

An inference whose middle term is both affirmatively and negatively tied to the major term is anvayavyatireki.

Its universal concomitance (vyapti) rests on both presence and absence together.

The affirmative side (anvaya) shows where the mark and the probandum occur together.

The negative side (vyatireka) shows where the absence of one accompanies absence of the other.

This joint character distinguishes it from the purely affirmative and purely negative types.