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Theorem nelaneq 9639
Description: A class is not an element of and equal to a class at the same time. Variant of elneq 9638 analogously to elnotel 9650 and en2lp 9646. (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 9638 . . 3 (𝐴𝐵𝐴𝐵)
2 orc 868 . . . 4 𝐴𝐵 → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
3 neneq 2946 . . . . 5 (𝐴𝐵 → ¬ 𝐴 = 𝐵)
43olcd 875 . . . 4 (𝐴𝐵 → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
52, 4ja 186 . . 3 ((𝐴𝐵𝐴𝐵) → (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
61, 5ax-mp 5 . 2 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵)
7 ianor 984 . 2 (¬ (𝐴𝐵𝐴 = 𝐵) ↔ (¬ 𝐴𝐵 ∨ ¬ 𝐴 = 𝐵))
86, 7mpbir 231 1 ¬ (𝐴𝐵𝐴 = 𝐵)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 395  wo 848   = wceq 1540  wcel 2108  wne 2940
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-12 2177  ax-ext 2708  ax-sep 5296  ax-pr 5432  ax-reg 9632
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-tru 1543  df-ex 1780  df-nf 1784  df-sb 2065  df-clab 2715  df-cleq 2729  df-clel 2816  df-ne 2941  df-ral 3062  df-rex 3071  df-v 3482  df-un 3956  df-sn 4627  df-pr 4629
This theorem is referenced by:  epinid0  9640
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