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Theorem 3anbi3i 1136
Description: Inference adding two conjuncts to each side of a biconditional. (Contributed by NM, 8-Sep-2006.)
Hypothesis
Ref Expression
3anbi1i.1  |-  ( ph  <->  ps )
Assertion
Ref Expression
3anbi3i  |-  ( ( ch  /\  th  /\  ph )  <->  ( ch  /\  th 
/\  ps ) )

Proof of Theorem 3anbi3i
StepHypRef Expression
1 biid 169 . 2  |-  ( ch  <->  ch )
2 biid 169 . 2  |-  ( th  <->  th )
3 3anbi1i.1 . 2  |-  ( ph  <->  ps )
41, 2, 33anbi123i 1132 1  |-  ( ( ch  /\  th  /\  ph )  <->  ( ch  /\  th 
/\  ps ) )
Colors of variables: wff set class
Syntax hints:    <-> wb 103    /\ w3a 924
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106
This theorem depends on definitions:  df-bi 115  df-3an 926
This theorem is referenced by:  dfer2  6291  cbvsum  10745
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