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Theorem xrnemnf 9557
Description: An extended real other than minus infinity is real or positive infinite. (Contributed by Mario Carneiro, 20-Aug-2015.)
Assertion
Ref Expression
xrnemnf  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  <->  ( A  e.  RR  \/  A  = +oo ) )

Proof of Theorem xrnemnf
StepHypRef Expression
1 pm5.61 783 . 2  |-  ( ( ( ( A  e.  RR  \/  A  = +oo )  \/  A  = -oo )  /\  -.  A  = -oo )  <->  ( ( A  e.  RR  \/  A  = +oo )  /\  -.  A  = -oo ) )
2 elxr 9556 . . . 4  |-  ( A  e.  RR*  <->  ( A  e.  RR  \/  A  = +oo  \/  A  = -oo ) )
3 df-3or 963 . . . 4  |-  ( ( A  e.  RR  \/  A  = +oo  \/  A  = -oo )  <->  ( ( A  e.  RR  \/  A  = +oo )  \/  A  = -oo ) )
42, 3bitri 183 . . 3  |-  ( A  e.  RR*  <->  ( ( A  e.  RR  \/  A  = +oo )  \/  A  = -oo ) )
5 df-ne 2307 . . 3  |-  ( A  =/= -oo  <->  -.  A  = -oo )
64, 5anbi12i 455 . 2  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  <->  ( (
( A  e.  RR  \/  A  = +oo )  \/  A  = -oo )  /\  -.  A  = -oo ) )
7 renemnf 7807 . . . . 5  |-  ( A  e.  RR  ->  A  =/= -oo )
8 pnfnemnf 7813 . . . . . 6  |- +oo  =/= -oo
9 neeq1 2319 . . . . . 6  |-  ( A  = +oo  ->  ( A  =/= -oo  <-> +oo  =/= -oo )
)
108, 9mpbiri 167 . . . . 5  |-  ( A  = +oo  ->  A  =/= -oo )
117, 10jaoi 705 . . . 4  |-  ( ( A  e.  RR  \/  A  = +oo )  ->  A  =/= -oo )
1211neneqd 2327 . . 3  |-  ( ( A  e.  RR  \/  A  = +oo )  ->  -.  A  = -oo )
1312pm4.71i 388 . 2  |-  ( ( A  e.  RR  \/  A  = +oo )  <->  ( ( A  e.  RR  \/  A  = +oo )  /\  -.  A  = -oo ) )
141, 6, 133bitr4i 211 1  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  <->  ( A  e.  RR  \/  A  = +oo ) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    /\ wa 103    <-> wb 104    \/ wo 697    \/ w3o 961    = wceq 1331    e. wcel 1480    =/= wne 2306   RRcr 7612   +oocpnf 7790   -oocmnf 7791   RR*cxr 7792
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-13 1491  ax-14 1492  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2119  ax-sep 4041  ax-pow 4093  ax-un 4350  ax-setind 4447  ax-cnex 7704  ax-resscn 7705
This theorem depends on definitions:  df-bi 116  df-3or 963  df-3an 964  df-tru 1334  df-fal 1337  df-nf 1437  df-sb 1736  df-clab 2124  df-cleq 2130  df-clel 2133  df-nfc 2268  df-ne 2307  df-nel 2402  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-pw 3507  df-sn 3528  df-pr 3529  df-uni 3732  df-pnf 7795  df-mnf 7796  df-xr 7797
This theorem is referenced by:  xaddf  9620  xaddval  9621  xaddnemnf  9633  xaddass  9645  xlesubadd  9659  xblss2ps  12562  xblss2  12563
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