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Theorem eqeqan1d 34003
Description: Implication of introducing a new equality. (Contributed by Peter Mazsa, 17-Apr-2019.)
Hypothesis
Ref Expression
eqeqan1d.1  |-  ( ph  ->  A  =  B )
Assertion
Ref Expression
eqeqan1d  |-  ( (
ph  /\  C  =  D )  ->  ( A  =  C  <->  B  =  D ) )

Proof of Theorem eqeqan1d
StepHypRef Expression
1 eqeqan1d.1 . 2  |-  ( ph  ->  A  =  B )
2 eqeq12 2635 . 2  |-  ( ( A  =  B  /\  C  =  D )  ->  ( A  =  C  <-> 
B  =  D ) )
31, 2sylan 488 1  |-  ( (
ph  /\  C  =  D )  ->  ( A  =  C  <->  B  =  D ) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    <-> wb 196    /\ wa 384    = wceq 1483
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-ext 2602
This theorem depends on definitions:  df-bi 197  df-an 386  df-ex 1705  df-cleq 2615
This theorem is referenced by: (None)
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