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Theorem neleqtrrd 2337
Description: If a class is not an element of another class, it is also not an element of an equal class. Deduction form. (Contributed by David Moews, 1-May-2017.)
Hypotheses
Ref Expression
neleqtrrd.1 (𝜑 → ¬ 𝐶𝐵)
neleqtrrd.2 (𝜑𝐴 = 𝐵)
Assertion
Ref Expression
neleqtrrd (𝜑 → ¬ 𝐶𝐴)

Proof of Theorem neleqtrrd
StepHypRef Expression
1 neleqtrrd.1 . 2 (𝜑 → ¬ 𝐶𝐵)
2 neleqtrrd.2 . . 3 (𝜑𝐴 = 𝐵)
32eleq2d 2308 . 2 (𝜑 → (𝐶𝐴𝐶𝐵))
41, 3mtbird 684 1 (𝜑 → ¬ 𝐶𝐴)
Colors of variables:    wff set class
This proof depends on syntax axioms:  ¬ wn 3  wi 4   = wceq 1402  wcel 2209
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-5 1500  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-4 1563  ax-17 1579  ax-ial 1587  ax-ext 2220
This proof depends on definitions:  df-bi 117  df-cleq 2231  df-clel 2234
This theorem is used by:  tfr1onlemsucaccv  6612  tfrcllemsucaccv  6625  zfz1isolemiso  11291  wrdlndm  11321  structiedg0val  16281  1hevtxdg0fi  16548
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