daf bit: Ketuvot 89

A woman who is divorced is entitled to her ketubah. What proof does she need to bring? The rabbis discuss whether she needs the ketubah (document), the bill of divorce (get), or both. The rabbis conclude that the get is sufficient to be paid the statutory amount, but they are concerned about fraud: what if she takes the get to two courts, winning two judgements, when she is only entitled to one payment? The get cannot be destroyed upon paying the first one because she needs it as proof that she may remarry. Rabbi Nachman proposes a practical solution: the court tears the get, but writes on it "we tore it up to signal payment, not because it's invalid". (89b)

(This is the last gemara before the next mishna, so if they return to the topic it won't be here. I wonder why they have to tear it at all? Why not just write on it "paid in full" and leave it at that?)