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Theorem ssneldd 3251
Description: If an element is not in a class, it is also not in a subclass of that class. Deduction form. (Contributed by David Moews, 1-May-2017.)
Hypotheses
Ref Expression
ssneld.1 (𝜑𝐴𝐵)
ssneldd.2 (𝜑 → ¬ 𝐶𝐵)
Assertion
Ref Expression
ssneldd (𝜑 → ¬ 𝐶𝐴)

Proof of Theorem ssneldd
StepHypRef Expression
1 ssneldd.2 . 2 (𝜑 → ¬ 𝐶𝐵)
2 ssneld.1 . . 3 (𝜑𝐴𝐵)
32ssneld 3250 . 2 (𝜑 → (¬ 𝐶𝐵 → ¬ 𝐶𝐴))
41, 3mpd 13 1 (𝜑 → ¬ 𝐶𝐴)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wcel 2209  wss 3220
This theorem was proved from 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-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-11 1559  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220
This theorem depends on definitions:  df-bi 117  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-in 3226  df-ss 3233
This theorem is referenced by:  0nelrel  4819  addnqprlemfl  7920  addnqprlemfu  7921  mulnqprlemfl  7936  mulnqprlemfu  7937  cauappcvgprlemladdru  8017  hashfibclem  11265  fprodntrivap  12334  fprodssdc  12340
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