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Theorem elab3gf 2807
Description: Membership in a class abstraction, with a weaker antecedent than elabgf 2800. (Contributed by NM, 6-Sep-2011.)
Hypotheses
Ref Expression
elab3gf.1  |-  F/_ x A
elab3gf.2  |-  F/ x ps
elab3gf.3  |-  ( x  =  A  ->  ( ph 
<->  ps ) )
Assertion
Ref Expression
elab3gf  |-  ( ( ps  ->  A  e.  B )  ->  ( A  e.  { x  |  ph }  <->  ps )
)

Proof of Theorem elab3gf
StepHypRef Expression
1 elab3gf.1 . . . 4  |-  F/_ x A
2 elab3gf.2 . . . 4  |-  F/ x ps
3 elab3gf.3 . . . 4  |-  ( x  =  A  ->  ( ph 
<->  ps ) )
41, 2, 3elabgf 2800 . . 3  |-  ( A  e.  { x  | 
ph }  ->  ( A  e.  { x  |  ph }  <->  ps )
)
54ibi 175 . 2  |-  ( A  e.  { x  | 
ph }  ->  ps )
61, 2, 3elabgf 2800 . . . 4  |-  ( A  e.  B  ->  ( A  e.  { x  |  ph }  <->  ps )
)
76imim2i 12 . . 3  |-  ( ( ps  ->  A  e.  B )  ->  ( ps  ->  ( A  e. 
{ x  |  ph } 
<->  ps ) ) )
8 bi2 129 . . 3  |-  ( ( A  e.  { x  |  ph }  <->  ps )  ->  ( ps  ->  A  e.  { x  |  ph } ) )
97, 8syli 37 . 2  |-  ( ( ps  ->  A  e.  B )  ->  ( ps  ->  A  e.  {
x  |  ph }
) )
105, 9impbid2 142 1  |-  ( ( ps  ->  A  e.  B )  ->  ( A  e.  { x  |  ph }  <->  ps )
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 104    = wceq 1316   F/wnf 1421    e. wcel 1465   {cab 2103   F/_wnfc 2245
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 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099
This theorem depends on definitions:  df-bi 116  df-tru 1319  df-nf 1422  df-sb 1721  df-clab 2104  df-cleq 2110  df-clel 2113  df-nfc 2247  df-v 2662
This theorem is referenced by:  elab3g  2808
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