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Theorem 19.8ad 28522
Description: If a wff is true, it is true for at least one instance. Deductive form of 19.8a 1763. (Contributed by DAW, 13-Feb-2017.)
Hypothesis
Ref Expression
19.8ad.1  |-  ( ph  ->  ps )
Assertion
Ref Expression
19.8ad  |-  ( ph  ->  E. x ps )

Proof of Theorem 19.8ad
StepHypRef Expression
1 19.8ad.1 . 2  |-  ( ph  ->  ps )
2 19.8a 1763 . 2  |-  ( ps 
->  E. x ps )
31, 2syl 16 1  |-  ( ph  ->  E. x ps )
Colors of variables: wff set class
Syntax hints:    -> wi 4   E.wex 1551
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1556  ax-5 1567  ax-17 1627  ax-9 1667  ax-8 1688  ax-11 1762
This theorem depends on definitions:  df-bi 179  df-ex 1552
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