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Theorem abn0r 3334
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 2088 . . 3 (𝑥 ∈ {𝑥𝜑} ↔ 𝜑)
21exbii 1552 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} ↔ ∃𝑥𝜑)
3 nfab1 2242 . . 3 𝑥{𝑥𝜑}
43n0rf 3322 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} → {𝑥𝜑} ≠ ∅)
52, 4sylbir 134 1 (∃𝑥𝜑 → {𝑥𝜑} ≠ ∅)
Colors of variables: wff set class
Syntax hints:  wi 4  wex 1436  wcel 1448  {cab 2086  wne 2267  c0 3310
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 584  ax-in2 585  ax-io 671  ax-5 1391  ax-7 1392  ax-gen 1393  ax-ie1 1437  ax-ie2 1438  ax-8 1450  ax-10 1451  ax-11 1452  ax-i12 1453  ax-bndl 1454  ax-4 1455  ax-17 1474  ax-i9 1478  ax-ial 1482  ax-i5r 1483  ax-ext 2082
This theorem depends on definitions:  df-bi 116  df-tru 1302  df-fal 1305  df-nf 1405  df-sb 1704  df-clab 2087  df-cleq 2093  df-clel 2096  df-nfc 2229  df-ne 2268  df-v 2643  df-dif 3023  df-nul 3311
This theorem is referenced by:  rabn0r  3336
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