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Theorem nfdh 1784
Description: Deduce that  x is not free in  ps in a context. (Contributed by Mario Carneiro, 24-Sep-2016.)
Hypotheses
Ref Expression
nfdh.1  |-  ( ph  ->  A. x ph )
nfdh.2  |-  ( ph  ->  ( ps  ->  A. x ps ) )
Assertion
Ref Expression
nfdh  |-  ( ph  ->  F/ x ps )

Proof of Theorem nfdh
StepHypRef Expression
1 nfdh.1 . . 3  |-  ( ph  ->  A. x ph )
21nfi 1561 . 2  |-  F/ x ph
3 nfdh.2 . 2  |-  ( ph  ->  ( ps  ->  A. x ps ) )
42, 3nfd 1783 1  |-  ( ph  ->  F/ x ps )
Colors of variables: wff set class
Syntax hints:    -> wi 4   A.wal 1550   F/wnf 1554
This theorem is referenced by:  hbimd  1835  ax11indalem  2276  ax11inda2ALT  2277  dvelimfwAUX7  29666
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  df-nf 1555
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