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Theorem bj-ssbn 32641
Description: The result of a substitution in the negation of a formula is the negation of the result of the same substitution in that formula. Proved from Tarski, ax-10 2019, bj-ax12 32634. Compare sbn 2391. (Contributed by BJ, 25-Dec-2020.)
Assertion
Ref Expression
bj-ssbn  |-  ([ t/ x]b  -.  ph  <->  -. [ t/ x]b ph )

Proof of Theorem bj-ssbn
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 df-ssb 32620 . 2  |-  ([ t/ x]b  -.  ph  <->  A. y
( y  =  t  ->  A. x ( x  =  y  ->  -.  ph ) ) )
2 alinexa 1770 . . . 4  |-  ( A. x ( x  =  y  ->  -.  ph )  <->  -. 
E. x ( x  =  y  /\  ph ) )
32imbi2i 326 . . 3  |-  ( ( y  =  t  ->  A. x ( x  =  y  ->  -.  ph )
)  <->  ( y  =  t  ->  -.  E. x
( x  =  y  /\  ph ) ) )
43albii 1747 . 2  |-  ( A. y ( y  =  t  ->  A. x
( x  =  y  ->  -.  ph ) )  <->  A. y ( y  =  t  ->  -.  E. x
( x  =  y  /\  ph ) ) )
5 alinexa 1770 . . 3  |-  ( A. y ( y  =  t  ->  -.  E. x
( x  =  y  /\  ph ) )  <->  -.  E. y ( y  =  t  /\  E. x ( x  =  y  /\  ph )
) )
6 bj-dfssb2 32640 . . 3  |-  ([ t/ x]b ph  <->  E. y ( y  =  t  /\  E. x ( x  =  y  /\  ph )
) )
75, 6xchbinxr 325 . 2  |-  ( A. y ( y  =  t  ->  -.  E. x
( x  =  y  /\  ph ) )  <->  -. [ t/ x]b ph )
81, 4, 73bitri 286 1  |-  ([ t/ x]b  -.  ph  <->  -. [ t/ x]b ph )
Colors of variables: wff setvar class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 196    /\ wa 384   A.wal 1481   E.wex 1704  [wssb 32619
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-10 2019  ax-12 2047
This theorem depends on definitions:  df-bi 197  df-an 386  df-ex 1705  df-ssb 32620
This theorem is referenced by: (None)
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