Axiom of foundation
= Axiom of foundation
{c}
{wiki=Axiom_of_regularity}
Every nonempty set $A$ has an element $x\in A$ such that $x\cap A=\varnothing$.
= Axiom of foundation
{c}
{wiki=Axiom_of_regularity}
Every nonempty set $A$ has an element $x\in A$ such that $x\cap A=\varnothing$.