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Theorem bj-ssbbi 32622
Description: Biconditional property for substitution, closed form. Specialization of biconditional. Uses only ax-1--5. Compare spsbbi 2402. (Contributed by BJ, 22-Dec-2020.)
Assertion
Ref Expression
bj-ssbbi  |-  ( A. x ( ph  <->  ps )  ->  ([ t/ x]b ph  <-> [ t/ x]b ps ) )

Proof of Theorem bj-ssbbi
StepHypRef Expression
1 biimp 205 . . . 4  |-  ( (
ph 
<->  ps )  ->  ( ph  ->  ps ) )
21alimi 1739 . . 3  |-  ( A. x ( ph  <->  ps )  ->  A. x ( ph  ->  ps ) )
3 bj-ssbim 32621 . . 3  |-  ( A. x ( ph  ->  ps )  ->  ([ t/ x]b ph  -> [ t/ x]b ps ) )
42, 3syl 17 . 2  |-  ( A. x ( ph  <->  ps )  ->  ([ t/ x]b ph  -> [ t/ x]b ps )
)
5 biimpr 210 . . . 4  |-  ( (
ph 
<->  ps )  ->  ( ps  ->  ph ) )
65alimi 1739 . . 3  |-  ( A. x ( ph  <->  ps )  ->  A. x ( ps 
->  ph ) )
7 bj-ssbim 32621 . . 3  |-  ( A. x ( ps  ->  ph )  ->  ([ t/ x]b ps  -> [ t/ x]b ph ) )
86, 7syl 17 . 2  |-  ( A. x ( ph  <->  ps )  ->  ([ t/ x]b ps  -> [ t/ x]b ph )
)
94, 8impbid 202 1  |-  ( A. x ( ph  <->  ps )  ->  ([ t/ x]b ph  <-> [ t/ x]b ps ) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    <-> wb 196   A.wal 1481  [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
This theorem depends on definitions:  df-bi 197  df-ssb 32620
This theorem is referenced by:  bj-ssbbii  32624
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