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Theorem 3netr3g 2239
Description: Substitution of equality into both sides of an inequality. (Contributed by NM, 24-Jul-2012.)
Hypotheses
Ref Expression
3netr3g.1  |-  ( ph  ->  A  =/=  B )
3netr3g.2  |-  A  =  C
3netr3g.3  |-  B  =  D
Assertion
Ref Expression
3netr3g  |-  ( ph  ->  C  =/=  D )

Proof of Theorem 3netr3g
StepHypRef Expression
1 3netr3g.1 . 2  |-  ( ph  ->  A  =/=  B )
2 3netr3g.2 . . 3  |-  A  =  C
3 3netr3g.3 . . 3  |-  B  =  D
42, 3neeq12i 2222 . 2  |-  ( A  =/=  B  <->  C  =/=  D )
51, 4sylib 127 1  |-  ( ph  ->  C  =/=  D )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1243    =/= wne 2204
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545  ax-5 1336  ax-gen 1338  ax-4 1400  ax-17 1419  ax-ext 2022
This theorem depends on definitions:  df-bi 110  df-cleq 2033  df-ne 2206
This theorem is referenced by: (None)
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