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Theorem nltmnf 9724
Description: No extended real is less than minus infinity. (Contributed by NM, 15-Oct-2005.)
Assertion
Ref Expression
nltmnf  |-  ( A  e.  RR*  ->  -.  A  < -oo )

Proof of Theorem nltmnf
StepHypRef Expression
1 mnfnre 7941 . . . . . . 7  |- -oo  e/  RR
21neli 2433 . . . . . 6  |-  -. -oo  e.  RR
32intnan 919 . . . . 5  |-  -.  ( A  e.  RR  /\ -oo  e.  RR )
43intnanr 920 . . . 4  |-  -.  (
( A  e.  RR  /\ -oo  e.  RR )  /\  A  <RR -oo )
5 pnfnemnf 7953 . . . . . 6  |- +oo  =/= -oo
65nesymi 2382 . . . . 5  |-  -. -oo  = +oo
76intnan 919 . . . 4  |-  -.  ( A  = -oo  /\ -oo  = +oo )
84, 7pm3.2ni 803 . . 3  |-  -.  (
( ( A  e.  RR  /\ -oo  e.  RR )  /\  A  <RR -oo )  \/  ( A  = -oo  /\ -oo  = +oo ) )
96intnan 919 . . . 4  |-  -.  ( A  e.  RR  /\ -oo  = +oo )
102intnan 919 . . . 4  |-  -.  ( A  = -oo  /\ -oo  e.  RR )
119, 10pm3.2ni 803 . . 3  |-  -.  (
( A  e.  RR  /\ -oo  = +oo )  \/  ( A  = -oo  /\ -oo  e.  RR ) )
128, 11pm3.2ni 803 . 2  |-  -.  (
( ( ( A  e.  RR  /\ -oo  e.  RR )  /\  A  <RR -oo )  \/  ( A  = -oo  /\ -oo  = +oo ) )  \/  ( ( A  e.  RR  /\ -oo  = +oo )  \/  ( A  = -oo  /\ -oo  e.  RR ) ) )
13 mnfxr 7955 . . 3  |- -oo  e.  RR*
14 ltxr 9711 . . 3  |-  ( ( A  e.  RR*  /\ -oo  e.  RR* )  ->  ( A  < -oo  <->  ( ( ( ( A  e.  RR  /\ -oo  e.  RR )  /\  A  <RR -oo )  \/  ( A  = -oo  /\ -oo  = +oo ) )  \/  ( ( A  e.  RR  /\ -oo  = +oo )  \/  ( A  = -oo  /\ -oo  e.  RR ) ) ) ) )
1513, 14mpan2 422 . 2  |-  ( A  e.  RR*  ->  ( A  < -oo  <->  ( ( ( ( A  e.  RR  /\ -oo  e.  RR )  /\  A  <RR -oo )  \/  ( A  = -oo  /\ -oo  = +oo ) )  \/  ( ( A  e.  RR  /\ -oo  = +oo )  \/  ( A  = -oo  /\ -oo  e.  RR ) ) ) ) )
1612, 15mtbiri 665 1  |-  ( A  e.  RR*  ->  -.  A  < -oo )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 103    <-> wb 104    \/ wo 698    = wceq 1343    e. wcel 2136   class class class wbr 3982   RRcr 7752    <RR cltrr 7757   +oocpnf 7930   -oocmnf 7931   RR*cxr 7932    < clt 7933
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 604  ax-in2 605  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-13 2138  ax-14 2139  ax-ext 2147  ax-sep 4100  ax-pow 4153  ax-pr 4187  ax-un 4411  ax-setind 4514  ax-cnex 7844  ax-resscn 7845
This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-fal 1349  df-nf 1449  df-sb 1751  df-eu 2017  df-mo 2018  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ne 2337  df-nel 2432  df-ral 2449  df-rex 2450  df-rab 2453  df-v 2728  df-dif 3118  df-un 3120  df-in 3122  df-ss 3129  df-pw 3561  df-sn 3582  df-pr 3583  df-op 3585  df-uni 3790  df-br 3983  df-opab 4044  df-xp 4610  df-pnf 7935  df-mnf 7936  df-xr 7937  df-ltxr 7938
This theorem is referenced by:  mnfle  9728  xrltnsym  9729  xrlttr  9731  xrltso  9732  xltnegi  9771  xposdif  9818  qbtwnxr  10193  xrmaxiflemab  11188  xrmaxltsup  11199  xrbdtri  11217  blssioo  13185
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