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Theorem abn0r 3516
Description: Nonempty class abstraction. (Contributed by Jim Kingdon, 1-Aug-2018.)
Assertion
Ref Expression
abn0r (∃𝑥𝜑 → {𝑥𝜑} ≠ ∅)

Proof of Theorem abn0r
StepHypRef Expression
1 abid 2217 . . 3 (𝑥 ∈ {𝑥𝜑} ↔ 𝜑)
21exbii 1651 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} ↔ ∃𝑥𝜑)
3 nfab1 2374 . . 3 𝑥{𝑥𝜑}
43n0rf 3504 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} → {𝑥𝜑} ≠ ∅)
52, 4sylbir 135 1 (∃𝑥𝜑 → {𝑥𝜑} ≠ ∅)
Colors of variables: wff set class
Syntax hints:  wi 4  wex 1538  wcel 2200  {cab 2215  wne 2400  c0 3491
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 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-ext 2211
This theorem depends on definitions:  df-bi 117  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-v 2801  df-dif 3199  df-nul 3492
This theorem is referenced by:  rabn0r  3518
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