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Theorem elimifd 29362
Description: Elimination of a conditional operator contained in a wff  ch. (Contributed by Thierry Arnoux, 25-Jan-2017.)
Hypotheses
Ref Expression
elimifd.1  |-  ( ph  ->  ( if ( ps ,  A ,  B
)  =  A  -> 
( ch  <->  th )
) )
elimifd.2  |-  ( ph  ->  ( if ( ps ,  A ,  B
)  =  B  -> 
( ch  <->  ta )
) )
Assertion
Ref Expression
elimifd  |-  ( ph  ->  ( ch  <->  ( ( ps  /\  th )  \/  ( -.  ps  /\  ta ) ) ) )

Proof of Theorem elimifd
StepHypRef Expression
1 exmid 431 . . . 4  |-  ( ps  \/  -.  ps )
21biantrur 527 . . 3  |-  ( ch  <->  ( ( ps  \/  -.  ps )  /\  ch )
)
32a1i 11 . 2  |-  ( ph  ->  ( ch  <->  ( ( ps  \/  -.  ps )  /\  ch ) ) )
4 andir 912 . . 3  |-  ( ( ( ps  \/  -.  ps )  /\  ch )  <->  ( ( ps  /\  ch )  \/  ( -.  ps  /\  ch ) ) )
54a1i 11 . 2  |-  ( ph  ->  ( ( ( ps  \/  -.  ps )  /\  ch )  <->  ( ( ps  /\  ch )  \/  ( -.  ps  /\  ch ) ) ) )
6 iftrue 4092 . . . . 5  |-  ( ps 
->  if ( ps ,  A ,  B )  =  A )
7 elimifd.1 . . . . 5  |-  ( ph  ->  ( if ( ps ,  A ,  B
)  =  A  -> 
( ch  <->  th )
) )
86, 7syl5 34 . . . 4  |-  ( ph  ->  ( ps  ->  ( ch 
<->  th ) ) )
98pm5.32d 671 . . 3  |-  ( ph  ->  ( ( ps  /\  ch )  <->  ( ps  /\  th ) ) )
10 iffalse 4095 . . . . 5  |-  ( -. 
ps  ->  if ( ps ,  A ,  B
)  =  B )
11 elimifd.2 . . . . 5  |-  ( ph  ->  ( if ( ps ,  A ,  B
)  =  B  -> 
( ch  <->  ta )
) )
1210, 11syl5 34 . . . 4  |-  ( ph  ->  ( -.  ps  ->  ( ch  <->  ta ) ) )
1312pm5.32d 671 . . 3  |-  ( ph  ->  ( ( -.  ps  /\ 
ch )  <->  ( -.  ps  /\  ta ) ) )
149, 13orbi12d 746 . 2  |-  ( ph  ->  ( ( ( ps 
/\  ch )  \/  ( -.  ps  /\  ch )
)  <->  ( ( ps 
/\  th )  \/  ( -.  ps  /\  ta )
) ) )
153, 5, 143bitrd 294 1  |-  ( ph  ->  ( ch  <->  ( ( ps  /\  th )  \/  ( -.  ps  /\  ta ) ) ) )
Colors of variables: wff setvar class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 196    \/ wo 383    /\ wa 384    = wceq 1483   ifcif 4086
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-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-if 4087
This theorem is referenced by:  elim2if  29363
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