Phaladeepika
एकस्मिन् भवने शून्ये न संशोध्यं कदाचन । द्वावग्रहौ चेद्यन्नयूनं तत्तुल्यं शोधयेद्द्वयोः ॥ २२॥
If one of the two Rasis (whether occupied or unoccupied) have no benefic dots, then also there is no reduction. If both the Rasis be unoccupied and have an unequal number of benefic dots, greater figure is to be replaced by the less.
english translation
ekasmin bhavane zUnye na saMzodhyaM kadAcana । dvAvagrahau cedyannayUnaM tattulyaM zodhayeddvayoH ॥ 22॥
hk transliteration by Sanscript