Ambiguities in the derivation of retrodictive probability
英文摘要：
The derivation of the quantum retrodictive probability formula involves an error, an ambiguity. The end result is correct because this error appears twice, in such a way as to cancel itself. In addition, however, the usual expression for the probability itself contains the same ambiguity; this may lead to errors in its application. A generally applicable method is given to avoid such ambiguities altogether.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
