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Theorem ralrals 17149
Description: If the universal part of a restricted "all some" statement holds, then the statement reduces to the existence of a member of  A satisfying its antecedent. This is the restricted counterpart of ralals 17155. (Contributed by Peter Mazsa and David A. Wheeler, 20-Jul-2026.)
Assertion
Ref Expression
ralrals  |-  ( A. x  e.  A  ( ph  ->  ps )  -> 
( A.E. x  e.  A ( ph  ->  ps )  <->  E. x  e.  A  ph ) )

Proof of Theorem ralrals
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 ibar 301 . . 3  |-  ( A. x  e.  A  ( ph  ->  ps )  -> 
( E. x  e.  A  ph  <->  ( A. x  e.  A  ( ph  ->  ps )  /\  E. x  e.  A  ph ) ) )
32bicomd 141 . 2  |-  ( A. x  e.  A  ( ph  ->  ps )  -> 
( ( A. x  e.  A  ( ph  ->  ps )  /\  E. x  e.  A  ph )  <->  E. x  e.  A  ph ) )
41, 3bitrid 192 1  |-  ( A. x  e.  A  ( ph  ->  ps )  -> 
( A.E. x  e.  A ( ph  ->  ps )  <->  E. x  e.  A  ph ) )
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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