The contour of a family of filters along a filter is a set-theoretic lower limit. Topologicity and regularity of convergences can be characterized with the aid of the contour operation. Contour inversion is studied, in particular, for iterated contours of sequential cascades. A related problem of continuous extension of maps between maximal elements of sequential cascades to full subcascades is solved in full generality.

中文翻译：

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连续级联之间的图连续扩展

沿着过滤器的一系列过滤器的轮廓是设定理论的下限。可以借助轮廓运算来表征收敛的拓扑性和规则性。研究了轮廓反演，特别是针对连续级联的迭代轮廓。完全笼统地解决了连续级联的最大元素之间的映射连续扩展到完整子级联的相关问题。