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Theorem nfabg 2984
Description: Bound-variable hypothesis builder for a class abstraction. Usage of this theorem is discouraged because it depends on ax-13 2389. See nfab 2983 for a version with more disjoint variable conditions, but not requiring ax-13 2389. (Contributed by Mario Carneiro, 11-Aug-2016.) (New usage is discouraged.)
Hypothesis
Ref Expression
nfabg.1 𝑥𝜑
Assertion
Ref Expression
nfabg 𝑥{𝑦𝜑}

Proof of Theorem nfabg
Dummy variable 𝑧 is distinct from all other variables.
StepHypRef Expression
1 nfabg.1 . . 3 𝑥𝜑
21nfsabg 2812 . 2 𝑥 𝑧 ∈ {𝑦𝜑}
32nfci 2963 1 𝑥{𝑦𝜑}
Colors of variables: wff setvar class
Syntax hints:  wnf 1783  {cab 2798  wnfc 2960
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1969  ax-7 2014  ax-10 2144  ax-11 2160  ax-12 2176  ax-13 2389
This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-tru 1539  df-ex 1780  df-nf 1784  df-sb 2069  df-clab 2799  df-nfc 2962
This theorem is referenced by:  nfaba1g  2986  nfiung  4944  nfiing  4945
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