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Theorem sbcbi2 2865
Description: Substituting into equivalent wff's gives equivalent results. (Contributed by Giovanni Mascellani, 9-Apr-2018.)
Assertion
Ref Expression
sbcbi2  |-  ( A. x ( ph  <->  ps )  ->  ( [. A  /  x ]. ph  <->  [. A  /  x ]. ps ) )

Proof of Theorem sbcbi2
StepHypRef Expression
1 abbi 2193 . . 3  |-  ( A. x ( ph  <->  ps )  <->  { x  |  ph }  =  { x  |  ps } )
2 eleq2 2143 . . 3  |-  ( { x  |  ph }  =  { x  |  ps }  ->  ( A  e. 
{ x  |  ph } 
<->  A  e.  { x  |  ps } ) )
31, 2sylbi 119 . 2  |-  ( A. x ( ph  <->  ps )  ->  ( A  e.  {
x  |  ph }  <->  A  e.  { x  |  ps } ) )
4 df-sbc 2817 . 2  |-  ( [. A  /  x ]. ph  <->  A  e.  { x  |  ph }
)
5 df-sbc 2817 . 2  |-  ( [. A  /  x ]. ps  <->  A  e.  { x  |  ps } )
63, 4, 53bitr4g 221 1  |-  ( A. x ( ph  <->  ps )  ->  ( [. A  /  x ]. ph  <->  [. A  /  x ]. ps ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 103   A.wal 1283    = wceq 1285    e. wcel 1434   {cab 2068   [.wsbc 2816
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-8 1436  ax-11 1438  ax-4 1441  ax-17 1460  ax-i9 1464  ax-ial 1468  ax-i5r 1469  ax-ext 2064
This theorem depends on definitions:  df-bi 115  df-tru 1288  df-nf 1391  df-sb 1687  df-clab 2069  df-cleq 2075  df-clel 2078  df-sbc 2817
This theorem is referenced by: (None)
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