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Theorem 19.44 1613
Description: Theorem 19.44 of [Margaris] p. 90. (Contributed by NM, 12-Mar-1993.)
Hypothesis
Ref Expression
19.44.1  |-  F/ x ps
Assertion
Ref Expression
19.44  |-  ( E. x ( ph  \/  ps )  <->  ( E. x ph  \/  ps ) )

Proof of Theorem 19.44
StepHypRef Expression
1 19.43 1560 . 2  |-  ( E. x ( ph  \/  ps )  <->  ( E. x ph  \/  E. x ps ) )
2 19.44.1 . . . 4  |-  F/ x ps
3219.9 1576 . . 3  |-  ( E. x ps  <->  ps )
43orbi2i 712 . 2  |-  ( ( E. x ph  \/  E. x ps )  <->  ( E. x ph  \/  ps )
)
51, 4bitri 182 1  |-  ( E. x ( ph  \/  ps )  <->  ( E. x ph  \/  ps ) )
Colors of variables: wff set class
Syntax hints:    <-> wb 103    \/ wo 662   F/wnf 1390   E.wex 1422
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-io 663  ax-5 1377  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-4 1441  ax-ial 1468
This theorem depends on definitions:  df-bi 115  df-nf 1391
This theorem is referenced by:  eeor  1626
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