Theorem unt0

Description: The null set is untangled. (Contributed by Scott Fenton, 10-Mar-2011) (Proof shortened by Andrew Salmon, 27-Aug-2011)

	Ref	Expression
Assertion	unt0	⊢ ∀ 𝑥 ∈ ∅ ¬ 𝑥 ∈ 𝑥

Proof

Step	Hyp	Ref	Expression
1		ral0	⊢ ∀ 𝑥 ∈ ∅ ¬ 𝑥 ∈ 𝑥