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Theorem bj-nfdiOLD 31512
Description: Obsolete proof temporarily kept here in view of the change of df-nf 1676 to nf2 2060. (Contributed by NM, 8-Mar-1995.) (Proof modification is discouraged.) (New usage is discouraged.)
Hypothesis
Ref Expression
bj-nfdiOLD.nf  |-  ( ph  ->  F/ x ph )
Assertion
Ref Expression
bj-nfdiOLD  |-  F/ x ph

Proof of Theorem bj-nfdiOLD
StepHypRef Expression
1 19.8a 1955 . . 3  |-  ( ph  ->  E. x ph )
2 bj-nfdiOLD.nf . . . 4  |-  ( ph  ->  F/ x ph )
3 nf2 2060 . . . 4  |-  ( F/ x ph  <->  ( E. x ph  ->  A. x ph ) )
42, 3sylib 201 . . 3  |-  ( ph  ->  ( E. x ph  ->  A. x ph )
)
51, 4mpd 15 . 2  |-  ( ph  ->  A. x ph )
65nfi 1682 1  |-  F/ x ph
Colors of variables: wff setvar class
Syntax hints:    -> wi 4   A.wal 1450   E.wex 1671   F/wnf 1675
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1677  ax-4 1690  ax-5 1766  ax-6 1813  ax-7 1859  ax-10 1932  ax-12 1950
This theorem depends on definitions:  df-bi 190  df-ex 1672  df-nf 1676
This theorem is referenced by: (None)
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