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Theorem renfdisj 7172
Description: The reals and the infinities are disjoint. (Contributed by NM, 25-Oct-2005.) (Proof shortened by Andrew Salmon, 19-Nov-2011.)
Assertion
Ref Expression
renfdisj  |-  ( RR 
i^i  { +oo , -oo } )  =  (/)

Proof of Theorem renfdisj
StepHypRef Expression
1 disj 3292 . 2  |-  ( ( RR  i^i  { +oo , -oo } )  =  (/) 
<-> 
A. x  e.  RR  -.  x  e.  { +oo , -oo } )
2 vex 2604 . . . . 5  |-  x  e. 
_V
32elpr 3419 . . . 4  |-  ( x  e.  { +oo , -oo }  <->  ( x  = +oo  \/  x  = -oo ) )
4 renepnf 7166 . . . . . 6  |-  ( x  e.  RR  ->  x  =/= +oo )
54necon2bi 2300 . . . . 5  |-  ( x  = +oo  ->  -.  x  e.  RR )
6 renemnf 7167 . . . . . 6  |-  ( x  e.  RR  ->  x  =/= -oo )
76necon2bi 2300 . . . . 5  |-  ( x  = -oo  ->  -.  x  e.  RR )
85, 7jaoi 668 . . . 4  |-  ( ( x  = +oo  \/  x  = -oo )  ->  -.  x  e.  RR )
93, 8sylbi 119 . . 3  |-  ( x  e.  { +oo , -oo }  ->  -.  x  e.  RR )
109con2i 589 . 2  |-  ( x  e.  RR  ->  -.  x  e.  { +oo , -oo } )
111, 10mprgbir 2421 1  |-  ( RR 
i^i  { +oo , -oo } )  =  (/)
Colors of variables: wff set class
Syntax hints:   -. wn 3    \/ wo 661    = wceq 1284    e. wcel 1433    i^i cin 2972   (/)c0 3251   {cpr 3399   RRcr 6980   +oocpnf 7150   -oocmnf 7151
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 576  ax-in2 577  ax-io 662  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-10 1436  ax-11 1437  ax-i12 1438  ax-bndl 1439  ax-4 1440  ax-13 1444  ax-14 1445  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468  ax-ext 2063  ax-sep 3896  ax-un 4188  ax-setind 4280  ax-cnex 7067  ax-resscn 7068
This theorem depends on definitions:  df-bi 115  df-3an 921  df-tru 1287  df-fal 1290  df-nf 1390  df-sb 1686  df-clab 2068  df-cleq 2074  df-clel 2077  df-nfc 2208  df-ne 2246  df-nel 2340  df-ral 2353  df-rex 2354  df-rab 2357  df-v 2603  df-dif 2975  df-un 2977  df-in 2979  df-ss 2986  df-nul 3252  df-pw 3384  df-sn 3404  df-pr 3405  df-uni 3602  df-pnf 7155  df-mnf 7156
This theorem is referenced by: (None)
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