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Theorem renfdisj 8167
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 3517 . 2  |-  ( ( RR  i^i  { +oo , -oo } )  =  (/) 
<-> 
A. x  e.  RR  -.  x  e.  { +oo , -oo } )
2 vex 2779 . . . . 5  |-  x  e. 
_V
32elpr 3664 . . . 4  |-  ( x  e.  { +oo , -oo }  <->  ( x  = +oo  \/  x  = -oo ) )
4 renepnf 8155 . . . . . 6  |-  ( x  e.  RR  ->  x  =/= +oo )
54necon2bi 2433 . . . . 5  |-  ( x  = +oo  ->  -.  x  e.  RR )
6 renemnf 8156 . . . . . 6  |-  ( x  e.  RR  ->  x  =/= -oo )
76necon2bi 2433 . . . . 5  |-  ( x  = -oo  ->  -.  x  e.  RR )
85, 7jaoi 718 . . . 4  |-  ( ( x  = +oo  \/  x  = -oo )  ->  -.  x  e.  RR )
93, 8sylbi 121 . . 3  |-  ( x  e.  { +oo , -oo }  ->  -.  x  e.  RR )
109con2i 628 . 2  |-  ( x  e.  RR  ->  -.  x  e.  { +oo , -oo } )
111, 10mprgbir 2566 1  |-  ( RR 
i^i  { +oo , -oo } )  =  (/)
Colors of variables: wff set class
Syntax hints:   -. wn 3    \/ wo 710    = wceq 1373    e. wcel 2178    i^i cin 3173   (/)c0 3468   {cpr 3644   RRcr 7959   +oocpnf 8139   -oocmnf 8140
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 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-13 2180  ax-14 2181  ax-ext 2189  ax-sep 4178  ax-un 4498  ax-setind 4603  ax-cnex 8051  ax-resscn 8052
This theorem depends on definitions:  df-bi 117  df-3an 983  df-tru 1376  df-fal 1379  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-ne 2379  df-nel 2474  df-ral 2491  df-rex 2492  df-rab 2495  df-v 2778  df-dif 3176  df-un 3178  df-in 3180  df-ss 3187  df-nul 3469  df-pw 3628  df-sn 3649  df-pr 3650  df-uni 3865  df-pnf 8144  df-mnf 8145
This theorem is referenced by: (None)
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