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Theorem sbcng 2949
Description: Move negation in and out of class substitution. (Contributed by NM, 16-Jan-2004.)
Assertion
Ref Expression
sbcng  |-  ( A  e.  V  ->  ( [. A  /  x ].  -.  ph  <->  -.  [. A  /  x ]. ph ) )

Proof of Theorem sbcng
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 dfsbcq2 2912 . 2  |-  ( y  =  A  ->  ( [ y  /  x ]  -.  ph  <->  [. A  /  x ].  -.  ph ) )
2 dfsbcq2 2912 . . 3  |-  ( y  =  A  ->  ( [ y  /  x ] ph  <->  [. A  /  x ]. ph ) )
32notbid 656 . 2  |-  ( y  =  A  ->  ( -.  [ y  /  x ] ph  <->  -.  [. A  /  x ]. ph ) )
4 sbn 1925 . 2  |-  ( [ y  /  x ]  -.  ph  <->  -.  [ y  /  x ] ph )
51, 3, 4vtoclbg 2747 1  |-  ( A  e.  V  ->  ( [. A  /  x ].  -.  ph  <->  -.  [. A  /  x ]. ph ) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 104    = wceq 1331    e. wcel 1480   [wsb 1735   [.wsbc 2909
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-in1 603  ax-in2 604  ax-io 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2121
This theorem depends on definitions:  df-bi 116  df-tru 1334  df-fal 1337  df-nf 1437  df-sb 1736  df-clab 2126  df-cleq 2132  df-clel 2135  df-nfc 2270  df-v 2688  df-sbc 2910
This theorem is referenced by:  sbcn1  2956  sbcnel12g  3019  sbcne12g  3020  difopab  4672  zsupcllemstep  11644
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