Zhunium

zhuny's blog


Project maintained by zhuny

Axiom of Choice

Statement

To any nonempty family $X$ whose elements are nonempty sets, there exists a function called a choice function

\[f : X \rightarrow \bigcup_{X_i \in X} X_i\]

such that $f(X_i) \in X_i$ for all $X_i \in X$

Equivalent Statement

ACwithEq

Order by alphabet

  1. (HMP) The Hausdorff Maximality Principle
  2. (WOP) The Well-Ordering Principle
  3. (ZL) Zorn’s Lemma

Prove

  1. AC to HMP
  2. HMP to ZL
  3. ZL to WOP
  4. WOP to AC