ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  abn0r GIF version

Theorem abn0r 3475
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 2184 . . 3 (𝑥 ∈ {𝑥𝜑} ↔ 𝜑)
21exbii 1619 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} ↔ ∃𝑥𝜑)
3 nfab1 2341 . . 3 𝑥{𝑥𝜑}
43n0rf 3463 . 2 (∃𝑥 𝑥 ∈ {𝑥𝜑} → {𝑥𝜑} ≠ ∅)
52, 4sylbir 135 1 (∃𝑥𝜑 → {𝑥𝜑} ≠ ∅)
Colors of variables: wff set class
Syntax hints:  wi 4  wex 1506  wcel 2167  {cab 2182  wne 2367  c0 3450
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 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ne 2368  df-v 2765  df-dif 3159  df-nul 3451
This theorem is referenced by:  rabn0r  3477
  Copyright terms: Public domain W3C validator