If the wife claims ignorance of the husband's impotence and the husband claims she knew, whose statement prevails?

Primary text

If the husband claims the wife knew of his impotence and she denies it, her statement prevails along with her oath, because the fundamental principle is her lack of prior knowledge. If she admits it, or if it is established through legal testimony (bayyinah), her marriage is confirmed, and her right to seek annulment is voided.