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Theorem eean 1854
Description: Rearrange existential quantifiers. (Contributed by NM, 27-Oct-2010.) (Revised by Mario Carneiro, 6-Oct-2016.)
Hypotheses
Ref Expression
eean.1  |-  F/ y
ph
eean.2  |-  F/ x ps
Assertion
Ref Expression
eean  |-  ( E. x E. y (
ph  /\  ps )  <->  ( E. x ph  /\  E. y ps ) )

Proof of Theorem eean
StepHypRef Expression
1 eean.1 . . . 4  |-  F/ y
ph
2119.42 1623 . . 3  |-  ( E. y ( ph  /\  ps )  <->  ( ph  /\  E. y ps ) )
32exbii 1541 . 2  |-  ( E. x E. y (
ph  /\  ps )  <->  E. x ( ph  /\  E. y ps ) )
4 eean.2 . . . 4  |-  F/ x ps
54nfex 1573 . . 3  |-  F/ x E. y ps
6519.41 1621 . 2  |-  ( E. x ( ph  /\  E. y ps )  <->  ( E. x ph  /\  E. y ps ) )
73, 6bitri 182 1  |-  ( E. x E. y (
ph  /\  ps )  <->  ( E. x ph  /\  E. y ps ) )
Colors of variables: wff set class
Syntax hints:    /\ wa 102    <-> wb 103   F/wnf 1394   E.wex 1426
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-4 1445  ax-ial 1472
This theorem depends on definitions:  df-bi 115  df-nf 1395
This theorem is referenced by:  eeanv  1855  reean  2535
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