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Theorem 3orbi123d 1253
Description: Deduction joining 3 equivalences to form equivalence of disjunctions. (Contributed by NM, 20-Apr-1994.)
Hypotheses
Ref Expression
bi3d.1  |-  ( ph  ->  ( ps  <->  ch )
)
bi3d.2  |-  ( ph  ->  ( th  <->  ta )
)
bi3d.3  |-  ( ph  ->  ( et  <->  ze )
)
Assertion
Ref Expression
3orbi123d  |-  ( ph  ->  ( ( ps  \/  th  \/  et )  <->  ( ch  \/  ta  \/  ze )
) )

Proof of Theorem 3orbi123d
StepHypRef Expression
1 bi3d.1 . . . 4  |-  ( ph  ->  ( ps  <->  ch )
)
2 bi3d.2 . . . 4  |-  ( ph  ->  ( th  <->  ta )
)
31, 2orbi12d 691 . . 3  |-  ( ph  ->  ( ( ps  \/  th )  <->  ( ch  \/  ta ) ) )
4 bi3d.3 . . 3  |-  ( ph  ->  ( et  <->  ze )
)
53, 4orbi12d 691 . 2  |-  ( ph  ->  ( ( ( ps  \/  th )  \/  et )  <->  ( ( ch  \/  ta )  \/ 
ze ) ) )
6 df-3or 937 . 2  |-  ( ( ps  \/  th  \/  et )  <->  ( ( ps  \/  th )  \/  et ) )
7 df-3or 937 . 2  |-  ( ( ch  \/  ta  \/  ze )  <->  ( ( ch  \/  ta )  \/ 
ze ) )
85, 6, 73bitr4g 280 1  |-  ( ph  ->  ( ( ps  \/  th  \/  et )  <->  ( ch  \/  ta  \/  ze )
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 177    \/ wo 358    \/ w3o 935
This theorem is referenced by:  moeq3  3111  soeq1  4522  solin  4526  ordtri3or  4613  dfwe2  4762  soinxp  4942  isosolem  6067  f1oweALT  6074  soxp  6459  sorpssi  6528  elfiun  7435  sornom  8157  ltsopr  8909  elz  10284  dyaddisj  19488  nb3graprlem2  21461  colinearalg  25849  axlowdim2  25899  axlowdim  25900  brcolinear2  25992  colineardim1  25995  colinearperm1  25996  frgraregorufr0  28441  3orbi123  28594
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8
This theorem depends on definitions:  df-bi 178  df-or 360  df-3or 937
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