1,711. "Get Pasul" vs. "Get Batel"
Hilchos Geirushin 2:7
Invalid gets are referred to as either “pasul” or “batel.” “Pasul” means that the get is invalid under Biblical law; “batel” means that the get is unacceptable based upon rabbinic enactment.
Hilchos Geirushin 2:8
If a man has a signed get and he instructs people to deliver it to his wife, they should do so (because we assume that the get is valid). Let’s say that the husband instructs people to write a get, sign it and deliver it to his wife, and they do so, after which the get is found to be invalid. In such a case, they may write another get; they may write even 100 more gets until the woman receives one that is valid.