What is the ruling on divorce based on a factual statement, such as, 'You are divorced if your brother is intelligent'?

Primary text

If the brother is known to be intelligent, the husband does not incur divorce (does not Hanith). If the brother is not intelligent, divorce occurs. This is treated like saying, 'By God, your brother is intelligent.' If there is doubt regarding the brother's intelligence, divorce does not occur, because the default status is the continuation of the marriage bond, which is not dissolved by doubt.