In the mathematical field of order theory, an ultrafilter on a given partially ordered set (or "poset") is a certain subset of namely a maximal filter on that is, a proper filter on that cannot be …

2024年1月13日 · An ultrafilter may be defined as a system of subsets satisfying three conditions: 1) the empty set is not included; 2) the intersection of two subsets in the system again belongs …

Ultrafilter GmbH is an innovotive manufacturer of high efficiency filters and purification components for compressed air, technical gases and fluids. Well known companies all over …

We survey applications of ultra lters and ultra lter constructions in two set theoretic contexts. In the rst setting, that of large cardinals, we explore a number of large cardinal properties and …

In the mathematical field of set theory, an ultrafilter on a set is a maximal filter on the set In other words, it is a collection of subsets of that satisfies the definition of a filter on and that is …

2018年8月17日 · Using this ultrafilter, you can use the ultrapower construction. But note that when working with ultrapowers, the main tool is Łoś's theorem, which can't be proven in ZF + BPIT. …

超濾 （ultrafiltration (UF) ）在膜过滤方法中，一种膜 孔径 尺寸大致在1.5 纳米 到0.2 微米 范围内的 过滤，其过滤动力为 液体 的压力差，过滤机理是通过膜孔筛除作用进行分离。 维基共享资 …

2025年3月5日 · Let S be a nonempty set, then an ultrafilter on S is a nonempty collection F of subsets of S having the following properties: 1. emptyset not in F. 2. If A,B in F, then A …

2023年11月18日 · 则称该滤子为超滤子 (ultrafilter). 令 $\mathcal {F}$ 是滤子. 类似拓扑的 base and subbase, 我们可以定义滤子的 base 和 subbase. 定义: 称 $\mathcal {B}$ 是 $\mathcal …

2013年2月9日 · 超滤公理：对任意非空集A⊊N，那么，集合A与A关于N的补集合其中必有一个属于滤器F，则该滤器F称为超滤器（Ultrafilter)。 超滤器不含空集。 注意：如果空集属于滤器F， …