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Theorem nelaneq 9288
Description: A class is not an element of and equal to a class at the same time. Variant of elneq 9287 analogously to elnotel 9298 and en2lp 9294. (Proposed by BJ, 18-Jun-2022.) (Contributed by AV, 18-Jun-2022.)
Assertion
Ref Expression
nelaneq ¬ (𝐴𝐵𝐴 = 𝐵)

Proof of Theorem nelaneq
StepHypRef Expression
1 elneq 9287 . . 3 (𝐴𝐵𝐴𝐵)
2 orc 863 . . . 4 𝐴𝐵 → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
3 neneq 2948 . . . . 5 (𝐴𝐵 → ¬ 𝐴 = 𝐵)
43olcd 870 . . . 4 (𝐴𝐵 → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
52, 4ja 186 . . 3 ((𝐴𝐵𝐴𝐵) → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
61, 5ax-mp 5 . 2 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵)
7 ianor 978 . 2 (¬ (𝐴𝐵𝐴 = 𝐵) ↔ (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
86, 7mpbir 230 1 ¬ (𝐴𝐵𝐴 = 𝐵)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 395  wo 843   = wceq 1539  wcel 2108  wne 2942
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-8 2110  ax-9 2118  ax-10 2139  ax-12 2173  ax-ext 2709  ax-sep 5218  ax-nul 5225  ax-pr 5347  ax-reg 9281
This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-tru 1542  df-fal 1552  df-ex 1784  df-nf 1788  df-sb 2069  df-clab 2716  df-cleq 2730  df-clel 2817  df-ne 2943  df-ral 3068  df-rex 3069  df-v 3424  df-dif 3886  df-un 3888  df-nul 4254  df-sn 4559  df-pr 4561
This theorem is referenced by:  epinid0  9289
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