What is the ruling regarding inheritance between a maternal aunt (khala), the mother of the paternal grandfather (umm abi umm), and the paternal uncle (amm umm)?

Primary text

The inheritance belongs to the maternal aunt. According to the view that posits the nullification of the cause, the maternal aunt receives one-half, the grandmother (umm abi umm) receives one-sixth, and the remainder goes to the paternal uncle. If the paternal uncle is not present, the estate is divided between the maternal aunt and the mother of the paternal grandfather on a four-part basis. If the grandmother is absent, the estate is split equally between the maternal aunt and the paternal uncle.