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Theorem sb8e 2093
Description: Substitution of variable in existential quantifier. (Contributed by NM, 12-Aug-1993.) (Revised by Mario Carneiro, 6-Oct-2016.)
Hypothesis
Ref Expression
sb5rf.1  F/
Assertion
Ref Expression
sb8e

Proof of Theorem sb8e
StepHypRef Expression
1 sb5rf.1 . . . . . 6  F/
21nfn 1793 . . . . 5  F/
32sb8 2092 . . . 4
4 sbn 2062 . . . . 5
54albii 1566 . . . 4
63, 5bitri 240 . . 3
76notbii 287 . 2
8 df-ex 1542 . 2
9 df-ex 1542 . 2
107, 8, 93bitr4i 268 1
Colors of variables: wff setvar class
Syntax hints:   wn 3   wb 176  wal 1540  wex 1541   F/wnf 1544  wsb 1648
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925
This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649
This theorem is referenced by:  exsbOLD  2131  sb8mo  2223
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