In this paper we start the investigation of a metric-related weakening of positive expansiveness. We will show some of its fundamental properties and relation to notions such as weak positive expansiveness and cover expansiveness. Finally, we will see how to use the Bing–Hanner modification to produce examples of positively subexpansive dynamical systems with nonmetrizable phase space.

中文翻译：

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正次膨胀动力系统

在本文中，我们开始调查与度量相关的正扩张性弱化。我们将展示它的一些基本属性以及与弱正扩张性和覆盖扩张性等概念的关系。最后，我们将看到如何使用 Bing-Hanner 修改来生成具有不可度量化相空间的正次膨胀动力系统的示例。