Theorem elnotel 9604

Description: A class cannot be an element of one of its elements. (Contributed by AV, 14-Jun-2022.)

Assertion

Ref	Expression
elnotel	⊢ (𝐴 ∈ 𝐵 → ¬ 𝐵 ∈ 𝐴)

Proof of Theorem elnotel

Step	Hyp	Ref	Expression
1		en2lp 9600	. 2 ⊢ ¬ (𝐴 ∈ 𝐵 ∧ 𝐵 ∈ 𝐴)
2	1	imnani 400	1 ⊢ (𝐴 ∈ 𝐵 → ¬ 𝐵 ∈ 𝐴)

Syntax hints:  ¬ wn 3   → wi 4   ∈ wcel 2098

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-10 2129  ax-12 2163  ax-ext 2697  ax-sep 5292  ax-nul 5299  ax-pr 5420  ax-reg 9586

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-nf 1778  df-sb 2060  df-clab 2704  df-cleq 2718  df-clel 2804  df-ne 2935  df-ral 3056  df-rex 3065  df-rab 3427  df-v 3470  df-dif 3946  df-un 3948  df-in 3950  df-ss 3960  df-nul 4318  df-if 4524  df-pw 4599  df-sn 4624  df-pr 4626  df-op 4630  df-br 5142  df-opab 5204  df-eprel 5573  df-fr 5624

This theorem is referenced by:  elnel  9605  preleqg  9609  mnurndlem1  43598