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Theorem abn0r 3439
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 2158 . . 3 (𝑥 ∈ {𝑥𝜑} ↔ 𝜑)
21exbii 1598 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} ↔ ∃𝑥𝜑)
3 nfab1 2314 . . 3 𝑥{𝑥𝜑}
43n0rf 3427 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} → {𝑥𝜑} ≠ ∅)
52, 4sylbir 134 1 (∃𝑥𝜑 → {𝑥𝜑} ≠ ∅)
Colors of variables: wff set class
Syntax hints:  wi 4  wex 1485  wcel 2141  {cab 2156  wne 2340  c0 3414
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152
This theorem depends on definitions:  df-bi 116  df-tru 1351  df-fal 1354  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-ne 2341  df-v 2732  df-dif 3123  df-nul 3415
This theorem is referenced by:  rabn0r  3441
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