What is the ruling if the condition for divorce involves the divorce of the collective wives ('my wives are divorced') based on swearing by the divorce of an individual wife?

Primary text

If a man states: 'If you swear by the divorce of Zaynab, then my wives are divorced.' Then he states: 'If you swear by the divorce of Umrah, then my wives are divorced.' Then he states: 'If you swear by the divorce of Hafsah, then my wives are divorced.' Each of the three wives incurs two divorces. When he stated the condition regarding Umrah's divorce, it caused him to swear by the divorce of Zaynab afterward, resulting in one divorce upon each wife due to the swearing by Umrah's divorce. When he then stated the condition regarding Hafsah's divorce, it caused him to swear by Umrah's and Zaynab's divorce, resulting in one divorce upon each wife due to the swearing by Umrah's divorce, but nothing occurs from the swearing by Zaynab's divorce as he has already incurred that consequence once and cannot incur it a second time.