Theorem unt0 36691

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

Assertion

Ref	Expression
unt0	⊢ ∀𝑥 ∈ ∅ ¬ 𝑥 ∈ 𝑥

Proof of Theorem unt0

Step	Hyp	Ref	Expression
1		ral0 4457	1 ⊢ ∀𝑥 ∈ ∅ ¬ 𝑥 ∈ 𝑥

This proof depends on syntax axioms:  ¬ wn 3  ∀wral 3080  ∅c0 4281

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-9 2157  ax-ext 2735

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-fal 1583  df-ex 1813  df-sb 2102  df-clab 2742  df-cleq 2755  df-ral 3081  df-dif 4050  df-nul 4282

This theorem is used by: (None)