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Theorem exmid0el 4237
Description: Excluded middle is equivalent to decidability of  (/) being an element of an arbitrary set. (Contributed by Jim Kingdon, 18-Jun-2022.)
Assertion
Ref Expression
exmid0el  |-  (EXMID  <->  A. xDECID  (/)  e.  x
)

Proof of Theorem exmid0el
StepHypRef Expression
1 exmidexmid 4229 . . 3  |-  (EXMID  -> DECID  (/)  e.  x )
21alrimiv 1888 . 2  |-  (EXMID  ->  A. xDECID  (/)  e.  x
)
3 ax-1 6 . . . 4  |-  (DECID  (/)  e.  x  ->  ( x  C_  { (/) }  -> DECID  (/) 
e.  x ) )
43alimi 1469 . . 3  |-  ( A. xDECID  (/) 
e.  x  ->  A. x
( x  C_  { (/) }  -> DECID  (/) 
e.  x ) )
5 df-exmid 4228 . . 3  |-  (EXMID  <->  A. x
( x  C_  { (/) }  -> DECID  (/) 
e.  x ) )
64, 5sylibr 134 . 2  |-  ( A. xDECID  (/) 
e.  x  -> EXMID )
72, 6impbii 126 1  |-  (EXMID  <->  A. xDECID  (/)  e.  x
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 105  DECID wdc 835   A.wal 1362    e. wcel 2167    C_ wss 3157   (/)c0 3450   {csn 3622  EXMIDwem 4227
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-14 2170  ax-ext 2178  ax-sep 4151  ax-nul 4159  ax-pow 4207
This theorem depends on definitions:  df-bi 117  df-dc 836  df-tru 1367  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-rab 2484  df-v 2765  df-dif 3159  df-in 3163  df-ss 3170  df-nul 3451  df-pw 3607  df-sn 3628  df-exmid 4228
This theorem is referenced by:  exmidel  4238
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