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Theorem elabgf1 13660
Description: One implication of elabgf 2868. (Contributed by BJ, 21-Nov-2019.)
Hypotheses
Ref Expression
elabgf1.nf1 𝑥𝐴
elabgf1.nf2 𝑥𝜓
elabgf1.1 (𝑥 = 𝐴 → (𝜑𝜓))
Assertion
Ref Expression
elabgf1 (𝐴 ∈ {𝑥𝜑} → 𝜓)

Proof of Theorem elabgf1
StepHypRef Expression
1 elabgf1.nf1 . . 3 𝑥𝐴
2 elabgf1.nf2 . . 3 𝑥𝜓
31, 2elabgft1 13659 . 2 (∀𝑥(𝑥 = 𝐴 → (𝜑𝜓)) → (𝐴 ∈ {𝑥𝜑} → 𝜓))
4 elabgf1.1 . 2 (𝑥 = 𝐴 → (𝜑𝜓))
53, 4mpg 1439 1 (𝐴 ∈ {𝑥𝜑} → 𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4   = wceq 1343  wnf 1448  wcel 2136  {cab 2151  wnfc 2295
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-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147
This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-v 2728
This theorem is referenced by:  elabf1  13662
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