Axiom of choiceW
Axiom of choice
Axiom of countable choiceW
Axiom of countable choice
Basis (linear algebra)W
Basis (linear algebra)
Cartesian productW
Cartesian product
Kőnig's lemmaW
Kőnig's lemma
Spanning treeW
Spanning tree
Uniformization (set theory)W
Uniformization (set theory)
Zorn's lemmaW
Zorn's lemma