Formal symptoms of relevance usually concern the propositional variables shared between the antecedent and the consequent of provable conditionals. Among the most famous results about such symptoms are Belnap’s early results showing that for sublogics of the strong relevant logic R, provable conditionals share a signed variable between antecedent and consequent. For logics weaker than R stronger variable sharing results are available. In 1984, Ross Brady gave one well-known example of such a result. As a corollary to the main result of the paper, we give a very simple proof of a related but strictly stronger result.

中文翻译：

---

深度相关性和超形式主义

相关性的形式症状通常涉及在可证明的条件句的前件和后件之间共享的命题变量。关于此类症状最著名的结果之一是贝尔纳普的早期结果，该结果表明，对于强相关逻辑 R 的子逻辑，可证明的条件在前件和后件之间共享一个有符号变量。对于弱于 R 的逻辑，可以获得更强的变量共享结果。1984 年，罗斯·布雷迪举了一个著名的例子来说明这种结果。作为论文主要结果的推论，我们给出了一个非常简单的证明，证明了一个相关但严格更强的结果。