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Theorem rexrals 17150
Description: If a member of  A satisfying the antecedent exists, then a restricted "all some" statement reduces to its universal part. This is the restricted counterpart of rexals 17156. (Contributed by Peter Mazsa and David A. Wheeler, 20-Jul-2026.)
Assertion
Ref Expression
rexrals  |-  ( E. x  e.  A  ph  ->  ( A.E. x  e.  A ( ph  ->  ps )  <->  A. x  e.  A  ( ph  ->  ps )
) )

Proof of Theorem rexrals
StepHypRef Expression
1 df-rals 17129 . 2  |-  ( A.E. x  e.  A
( ph  ->  ps )  <->  ( A. x  e.  A  ( ph  ->  ps )  /\  E. x  e.  A  ph ) )
2 iba 300 . . 3  |-  ( E. x  e.  A  ph  ->  ( A. x  e.  A  ( ph  ->  ps )  <->  ( A. x  e.  A  ( ph  ->  ps )  /\  E. x  e.  A  ph )
) )
32bicomd 141 . 2  |-  ( E. x  e.  A  ph  ->  ( ( A. x  e.  A  ( ph  ->  ps )  /\  E. x  e.  A  ph )  <->  A. x  e.  A  (
ph  ->  ps ) ) )
41, 3bitrid 192 1  |-  ( E. x  e.  A  ph  ->  ( A.E. x  e.  A ( ph  ->  ps )  <->  A. x  e.  A  ( ph  ->  ps )
) )
Colors of variables:    wff set class
This proof depends on syntax axioms:    -> wi 4    /\ wa 104    <-> wb 105   A.wral 2528   E.wrex 2529   A.E.wrals 17127
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108
This proof depends on definitions:  df-bi 117  df-rals 17129
This theorem is used by: (None)
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