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Theorem reg2exmid 4446
Description: If any inhabited set has a minimal element (when expressed by  C_), excluded middle follows. (Contributed by Jim Kingdon, 2-Oct-2021.)
Hypothesis
Ref Expression
reg2exmid.1  |-  A. z
( E. w  w  e.  z  ->  E. x  e.  z  A. y  e.  z  x  C_  y
)
Assertion
Ref Expression
reg2exmid  |-  ( ph  \/  -.  ph )
Distinct variable groups:    ph, w, z    ph, x, z, y

Proof of Theorem reg2exmid
Dummy variable  u is distinct from all other variables.
StepHypRef Expression
1 eqid 2137 . . . 4  |-  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  =  { u  e.  { (/) ,  { (/) } }  | 
( u  =  { (/)
}  \/  ( u  =  (/)  /\  ph )
) }
21regexmidlemm 4442 . . 3  |-  E. w  w  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }
3 reg2exmid.1 . . . 4  |-  A. z
( E. w  w  e.  z  ->  E. x  e.  z  A. y  e.  z  x  C_  y
)
4 pp0ex 4108 . . . . . 6  |-  { (/) ,  { (/) } }  e.  _V
54rabex 4067 . . . . 5  |-  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  e.  _V
6 eleq2 2201 . . . . . . 7  |-  ( z  =  { u  e. 
{ (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  ( w  e.  z  <->  w  e.  { u  e.  { (/) ,  { (/) } }  | 
( u  =  { (/)
}  \/  ( u  =  (/)  /\  ph )
) } ) )
76exbidv 1797 . . . . . 6  |-  ( z  =  { u  e. 
{ (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  ( E. w  w  e.  z  <->  E. w  w  e. 
{ u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } ) )
8 raleq 2624 . . . . . . 7  |-  ( z  =  { u  e. 
{ (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  ( A. y  e.  z  x  C_  y  <->  A. y  e.  { u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } x  C_  y ) )
98rexeqbi1dv 2633 . . . . . 6  |-  ( z  =  { u  e. 
{ (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  ( E. x  e.  z 
A. y  e.  z  x  C_  y  <->  E. x  e.  { u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y ) )
107, 9imbi12d 233 . . . . 5  |-  ( z  =  { u  e. 
{ (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  ( ( E. w  w  e.  z  ->  E. x  e.  z  A. y  e.  z  x  C_  y
)  <->  ( E. w  w  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) }  ->  E. x  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y ) ) )
115, 10spcv 2774 . . . 4  |-  ( A. z ( E. w  w  e.  z  ->  E. x  e.  z  A. y  e.  z  x  C_  y )  ->  ( E. w  w  e.  { u  e.  { (/) ,  { (/) } }  | 
( u  =  { (/)
}  \/  ( u  =  (/)  /\  ph )
) }  ->  E. x  e.  { u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y ) )
123, 11ax-mp 5 . . 3  |-  ( E. w  w  e.  {
u  e.  { (/) ,  { (/) } }  | 
( u  =  { (/)
}  \/  ( u  =  (/)  /\  ph )
) }  ->  E. x  e.  { u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y )
132, 12ax-mp 5 . 2  |-  E. x  e.  { u  e.  { (/)
,  { (/) } }  |  ( u  =  { (/) }  \/  (
u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y
141reg2exmidlema 4444 . 2  |-  ( E. x  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } A. y  e.  { u  e.  { (/) ,  { (/) } }  |  ( u  =  { (/) }  \/  ( u  =  (/)  /\  ph ) ) } x  C_  y  ->  ( ph  \/  -.  ph ) )
1513, 14ax-mp 5 1  |-  ( ph  \/  -.  ph )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 103    \/ wo 697   A.wal 1329    = wceq 1331   E.wex 1468    e. wcel 1480   A.wral 2414   E.wrex 2415   {crab 2418    C_ wss 3066   (/)c0 3358   {csn 3522   {cpr 3523
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 603  ax-in2 604  ax-io 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-14 1492  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2119  ax-sep 4041  ax-nul 4049  ax-pow 4093
This theorem depends on definitions:  df-bi 116  df-tru 1334  df-nf 1437  df-sb 1736  df-clab 2124  df-cleq 2130  df-clel 2133  df-nfc 2268  df-ral 2419  df-rex 2420  df-rab 2423  df-v 2683  df-dif 3068  df-un 3070  df-in 3072  df-ss 3079  df-nul 3359  df-pw 3507  df-sn 3528  df-pr 3529
This theorem is referenced by: (None)
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