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Theorem csbiebg 3144
Description: Bidirectional conversion between an implicit class substitution hypothesis  x  =  A  ->  B  =  C and its explicit substitution equivalent. (Contributed by NM, 24-Mar-2013.) (Revised by Mario Carneiro, 11-Dec-2016.)
Hypothesis
Ref Expression
csbiebg.2  |-  F/_ x C
Assertion
Ref Expression
csbiebg  |-  ( A  e.  V  ->  ( A. x ( x  =  A  ->  B  =  C )  <->  [_ A  /  x ]_ B  =  C ) )
Distinct variable group:    x, A
Allowed substitution hints:    B( x)    C( x)    V( x)

Proof of Theorem csbiebg
Dummy variable  a is distinct from all other variables.
StepHypRef Expression
1 eqeq2 2217 . . . 4  |-  ( a  =  A  ->  (
x  =  a  <->  x  =  A ) )
21imbi1d 231 . . 3  |-  ( a  =  A  ->  (
( x  =  a  ->  B  =  C )  <->  ( x  =  A  ->  B  =  C ) ) )
32albidv 1848 . 2  |-  ( a  =  A  ->  ( A. x ( x  =  a  ->  B  =  C )  <->  A. x
( x  =  A  ->  B  =  C ) ) )
4 csbeq1 3104 . . 3  |-  ( a  =  A  ->  [_ a  /  x ]_ B  = 
[_ A  /  x ]_ B )
54eqeq1d 2216 . 2  |-  ( a  =  A  ->  ( [_ a  /  x ]_ B  =  C  <->  [_ A  /  x ]_ B  =  C )
)
6 vex 2779 . . 3  |-  a  e. 
_V
7 csbiebg.2 . . 3  |-  F/_ x C
86, 7csbieb 3143 . 2  |-  ( A. x ( x  =  a  ->  B  =  C )  <->  [_ a  /  x ]_ B  =  C )
93, 5, 8vtoclbg 2839 1  |-  ( A  e.  V  ->  ( A. x ( x  =  A  ->  B  =  C )  <->  [_ A  /  x ]_ B  =  C ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 105   A.wal 1371    = wceq 1373    e. wcel 2178   F/_wnfc 2337   [_csb 3101
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2189
This theorem depends on definitions:  df-bi 117  df-3an 983  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-v 2778  df-sbc 3006  df-csb 3102
This theorem is referenced by: (None)
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