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Theorem neleq12d 2441
Description: Equality theorem for negated membership. (Contributed by FL, 10-Aug-2016.)
Hypotheses
Ref Expression
neleq12d.1  |-  ( ph  ->  A  =  B )
neleq12d.2  |-  ( ph  ->  C  =  D )
Assertion
Ref Expression
neleq12d  |-  ( ph  ->  ( A  e/  C  <->  B  e/  D ) )

Proof of Theorem neleq12d
StepHypRef Expression
1 neleq12d.1 . . 3  |-  ( ph  ->  A  =  B )
2 neleq1 2439 . . 3  |-  ( A  =  B  ->  ( A  e/  C  <->  B  e/  C ) )
31, 2syl 14 . 2  |-  ( ph  ->  ( A  e/  C  <->  B  e/  C ) )
4 neleq12d.2 . . 3  |-  ( ph  ->  C  =  D )
5 neleq2 2440 . . 3  |-  ( C  =  D  ->  ( B  e/  C  <->  B  e/  D ) )
64, 5syl 14 . 2  |-  ( ph  ->  ( B  e/  C  <->  B  e/  D ) )
73, 6bitrd 187 1  |-  ( ph  ->  ( A  e/  C  <->  B  e/  D ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 104    = wceq 1348    e/ wnel 2435
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 609  ax-in2 610  ax-5 1440  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-4 1503  ax-17 1519  ax-ial 1527  ax-ext 2152
This theorem depends on definitions:  df-bi 116  df-cleq 2163  df-clel 2166  df-nel 2436
This theorem is referenced by: (None)
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