Axiom:Filter on Set Axioms
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Definition
Let $S$ be a set.
Let $\powerset S$ denote the power set of $S$.
Let $\FF \subset \powerset S$.
Axioms 1
$\FF$ is said to satisfy the filter on set axioms if and only if:
\((\text F 1)\) | $:$ | \(\ds S \in \FF \) | |||||||
\((\text F 2)\) | $:$ | \(\ds \O \notin \FF \) | |||||||
\((\text F 3)\) | $:$ | \(\ds U, V \in \FF \implies U \cap V \in \FF \) | |||||||
\((\text F 4)\) | $:$ | \(\ds \forall U \in \FF: U \subseteq V \subseteq S \implies V \in \FF \) |
Axioms 2
$\FF$ is said to satisfy the filter on set axioms if and only if:
\((\text F 1)\) | $:$ | \(\ds S \in \FF \) | |||||||
\((\text F 2)\) | $:$ | \(\ds \O \notin \FF \) | |||||||
\((\text F 3)\) | $:$ | \(\ds \forall n \in \N: U_1, \ldots, U_n \in \FF \implies \bigcap_{i \mathop = 1}^n U_i \in \FF \) | |||||||
\((\text F 4)\) | $:$ | \(\ds \forall U \in \FF: U \subseteq V \subseteq S \implies V \in \FF \) |
Also see
- Results about filters can be found here.