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Theorem alsc1d 10952
Description: Deduction rule: Given "all some" applied to a class, you can extract the "for all" part. (Contributed by David A. Wheeler, 20-Oct-2018.)
Hypothesis
Ref Expression
alsc1d.1  |-  ( ph  ->  A.! x  e.  A ps )
Assertion
Ref Expression
alsc1d  |-  ( ph  ->  A. x  e.  A  ps )

Proof of Theorem alsc1d
StepHypRef Expression
1 alsc1d.1 . . 3  |-  ( ph  ->  A.! x  e.  A ps )
2 df-alsc 10948 . . 3  |-  ( A.! x  e.  A ps  <->  ( A. x  e.  A  ps  /\  E. x  x  e.  A ) )
31, 2sylib 120 . 2  |-  ( ph  ->  ( A. x  e.  A  ps  /\  E. x  x  e.  A
) )
43simpld 110 1  |-  ( ph  ->  A. x  e.  A  ps )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 102   E.wex 1422    e. wcel 1434   A.wral 2349   A.!walsc 10946
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104
This theorem depends on definitions:  df-bi 115  df-alsc 10948
This theorem is referenced by: (None)
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