Ketubot 22: Self-incrimination, to a Degree

What is a "Beit Din chatzuf"? When the court isn't quite proper, but its acts are upheld. Also, a new mishnah who speaks about herself as having been married and is now divorced - we know that she is believed. And what of this principle of the same mouth permitting and prohibiting, where's its source? Plus, backing up one's statement with a rationale. Also, keeping the hordes away with a false claim of marriage. || Talmudic Principles: chatikha de-isura; amatla.