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Theorem neleq12d 2448
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 2446 . . 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 2447 . . 3  |-  ( C  =  D  ->  ( B  e/  C  <->  B  e/  D ) )
64, 5syl 14 . 2  |-  ( ph  ->  ( B  e/  C  <->  B  e/  D ) )
73, 6bitrd 188 1  |-  ( ph  ->  ( A  e/  C  <->  B  e/  D ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 105    = wceq 1353    e/ wnel 2442
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-in1 614  ax-in2 615  ax-5 1447  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-4 1510  ax-17 1526  ax-ial 1534  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-cleq 2170  df-clel 2173  df-nel 2443
This theorem is referenced by: (None)
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