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Theorem nnregexmid 4725
Description: If inhabited sets of natural numbers always have minimal elements, excluded middle follows. The argument is essentially the same as regexmid 4639 and the larger lesson is that although natural numbers may behave "non-constructively" even in a constructive set theory (for example see nndceq 6710 or nntri3or 6704), sets of natural numbers are a different animal. (Contributed by Jim Kingdon, 6-Sep-2019.)
Hypothesis
Ref Expression
nnregexmid.1  |-  ( ( x  C_  om  /\  E. y  y  e.  x
)  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )
Assertion
Ref Expression
nnregexmid  |-  ( ph  \/  -.  ph )
Distinct variable group:    ph, x, y, z

Proof of Theorem nnregexmid
Dummy variable  w is distinct from all other variables.
StepHypRef Expression
1 ssrab2 3313 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  {
(/) ,  { (/) } }
2 peano1 4698 . . . . 5  |-  (/)  e.  om
3 suc0 4514 . . . . . 6  |-  suc  (/)  =  { (/)
}
4 peano2 4699 . . . . . . 7  |-  ( (/)  e.  om  ->  suc  (/)  e.  om )
52, 4ax-mp 5 . . . . . 6  |-  suc  (/)  e.  om
63, 5eqeltrri 2305 . . . . 5  |-  { (/) }  e.  om
7 prssi 3836 . . . . 5  |-  ( (
(/)  e.  om  /\  { (/)
}  e.  om )  ->  { (/) ,  { (/) } }  C_  om )
82, 6, 7mp2an 426 . . . 4  |-  { (/) ,  { (/) } }  C_  om
91, 8sstri 3237 . . 3  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om
10 eqid 2231 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  =  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }
1110regexmidlemm 4636 . . 3  |-  E. y 
y  e.  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }
12 pp0ex 4285 . . . . 5  |-  { (/) ,  { (/) } }  e.  _V
1312rabex 4239 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  e.  _V
14 sseq1 3251 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( x  C_  om  <->  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om ) )
15 eleq2 2295 . . . . . . 7  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( y  e.  x  <->  y  e.  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } ) )
1615exbidv 1873 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( E. y  y  e.  x  <->  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )
1714, 16anbi12d 473 . . . . 5  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( x  C_  om  /\  E. y  y  e.  x
)  <->  ( { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om 
/\  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
18 eleq2 2295 . . . . . . . . . 10  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( z  e.  x  <->  z  e.  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } ) )
1918notbid 673 . . . . . . . . 9  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( -.  z  e.  x  <->  -.  z  e.  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) } ) )
2019imbi2d 230 . . . . . . . 8  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( z  e.  y  ->  -.  z  e.  x )  <->  ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
2120albidv 1872 . . . . . . 7  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( A. z ( z  e.  y  ->  -.  z  e.  x )  <->  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
2215, 21anbi12d 473 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
)  <->  ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) )
2322exbidv 1873 . . . . 5  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( E. y ( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x ) )  <->  E. y
( y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) )
2417, 23imbi12d 234 . . . 4  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( ( x  C_  om 
/\  E. y  y  e.  x )  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )  <->  ( ( { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  C_  om  /\  E. y  y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } )  ->  E. y ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) ) )
25 nnregexmid.1 . . . 4  |-  ( ( x  C_  om  /\  E. y  y  e.  x
)  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )
2613, 24, 25vtocl 2859 . . 3  |-  ( ( { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  C_  om 
/\  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } )  ->  E. y ( y  e.  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
279, 11, 26mp2an 426 . 2  |-  E. y
( y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )
2810regexmidlem1 4637 . 2  |-  ( E. y ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )  ->  ( ph  \/  -.  ph ) )
2927, 28ax-mp 5 1  |-  ( ph  \/  -.  ph )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    \/ wo 716   A.wal 1396    = wceq 1398   E.wex 1541    e. wcel 2202   {crab 2515    C_ wss 3201   (/)c0 3496   {csn 3673   {cpr 3674   suc csuc 4468   omcom 4694
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 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2204  ax-14 2205  ax-ext 2213  ax-sep 4212  ax-nul 4220  ax-pow 4270  ax-pr 4305  ax-un 4536
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ral 2516  df-rex 2517  df-rab 2520  df-v 2805  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-pw 3658  df-sn 3679  df-pr 3680  df-uni 3899  df-int 3934  df-suc 4474  df-iom 4695
This theorem is referenced by: (None)
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