Epistemic decision theory produces arguments with both normative and mathematical premises. I begin by arguing that philosophers should care about whether the mathematical premises (1) are true, (2) are strong, and (3) admit simple proofs. I then discuss a theorem that Briggs and Pettigrew (Noûs 54(1):162–181, 2020) use as a premise in a novel accuracy-dominance argument for conditionalization. I argue that the theorem and its proof can be improved in a number of ways. First, I present a counterexample that shows that one of the theorem’s claims is false. As a result of this, Briggs and Pettigrew’s argument for conditionalization is unsound. I go on to explore how a sound accuracy-dominance argument for conditionalization might be recovered. In the course of doing this, I prove two new theorems that correct and strengthen the result reported by Briggs and Pettigrew. I show how my results can be combined with various normative premises to produce sound arguments for conditionalization. I also show that my results can be used to support normative conclusions that are stronger than the one that Briggs and Pettigrew’s argument supports. Finally, I show that Briggs and Pettigrew’s proofs can be simplified considerably.

认识论决策理论产生的论点具有规范性和数学性前提。首先，我认为哲学家应该关注数学前提（1）是否正确，（2）强和（3）接受简单的证明。然后，我讨论一个定理，布里格斯和佩蒂格鲁夫（Noûs54（1）：162-181，2020）以此为前提，提出了一种新的条件支配的精度支配论证。我认为该定理及其证明可以通过多种方式加以改进。首先，我提出一个反例，表明该定理的一个主张是错误的。结果，布里格斯和佩蒂格鲁夫提出的条件化论据是不正确的。我继续探讨如何恢复条件化的正确性和准确性。在这样做的过程中，我证明了两个新定理，它们可以纠正和加强Briggs和Pettigrew报告的结果。我展示了如何将我的结果与各种规范前提结合起来以产生有条件的合理论证。我还表明，我的结果可用于支持比Briggs和Pettigrew的论证所支持的结论更强的规范性结论。最后，我证明Briggs和Pettigrew的证明可以大大简化。