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Theorem rexbii2 2518
Description: Inference adding different restricted existential quantifiers to each side of an equivalence. (Contributed by NM, 4-Feb-2004.)
Hypothesis
Ref Expression
rexbii2.1  |-  ( ( x  e.  A  /\  ph )  <->  ( x  e.  B  /\  ps )
)
Assertion
Ref Expression
rexbii2  |-  ( E. x  e.  A  ph  <->  E. x  e.  B  ps )

Proof of Theorem rexbii2
StepHypRef Expression
1 rexbii2.1 . . 3  |-  ( ( x  e.  A  /\  ph )  <->  ( x  e.  B  /\  ps )
)
21exbii 1629 . 2  |-  ( E. x ( x  e.  A  /\  ph )  <->  E. x ( x  e.  B  /\  ps )
)
3 df-rex 2491 . 2  |-  ( E. x  e.  A  ph  <->  E. x ( x  e.  A  /\  ph )
)
4 df-rex 2491 . 2  |-  ( E. x  e.  B  ps  <->  E. x ( x  e.  B  /\  ps )
)
52, 3, 43bitr4i 212 1  |-  ( E. x  e.  A  ph  <->  E. x  e.  B  ps )
Colors of variables: wff set class
Syntax hints:    /\ wa 104    <-> wb 105   E.wex 1516    e. wcel 2177   E.wrex 2486
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-5 1471  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-4 1534  ax-ial 1558
This theorem depends on definitions:  df-bi 117  df-rex 2491
This theorem is referenced by:  rexeqbii  2520  rexbiia  2522  rexrab  2940  rexdifpr  3666  rexdifsn  3771  bnd2  4225  suplocsrlemb  7939  rexuz2  9722  rexrp  9818  rexuz3  11376  4sqexercise1  12796
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