There are several ways to quantify over public announcements. The most notable are reflected in arbitrary, group, and coalition announcement logics (APAL, GAL, and CAL correspondingly), with the latter being the least studied so far. In the present work, we consider coalition announcements through the lens of group announcements, and provide a complete axiomatisation of a logic with coalition announcements. To achieve this, we employ a generalisation of group announcements. Moreover, we study some logical properties of both coalition and group announcements that have not been studied before.

中文翻译：

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联盟和相对化的群体公告逻辑

有几种方法可以量化公开公告。最值得注意的是任意、组和联盟公告逻辑（相应的 APAL、GAL 和 CAL），而后者目前研究最少。在目前的工作中，我们通过群体公告的视角考虑联盟公告，并提供一个完整的联盟公告逻辑公理化。为了实现这一点，我们采用了群体公告的概括。此外，我们研究了联盟和团体公告的一些以前没有研究过的逻辑特性。