ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  mnflt Unicode version

Theorem mnflt 8704
Description: Minus infinity is less than any (finite) real. (Contributed by NM, 14-Oct-2005.)
Assertion
Ref Expression
mnflt  |-  ( A  e.  RR  -> -oo  <  A )

Proof of Theorem mnflt
StepHypRef Expression
1 eqid 2040 . . . 4  |- -oo  = -oo
2 olc 632 . . . 4  |-  ( ( -oo  = -oo  /\  A  e.  RR )  ->  ( ( -oo  e.  RR  /\  A  = +oo )  \/  ( -oo  = -oo  /\  A  e.  RR ) ) )
31, 2mpan 400 . . 3  |-  ( A  e.  RR  ->  (
( -oo  e.  RR  /\  A  = +oo )  \/  ( -oo  = -oo  /\  A  e.  RR ) ) )
43olcd 653 . 2  |-  ( A  e.  RR  ->  (
( ( ( -oo  e.  RR  /\  A  e.  RR )  /\ -oo  <RR  A )  \/  ( -oo  = -oo  /\  A  = +oo ) )  \/  ( ( -oo  e.  RR  /\  A  = +oo )  \/  ( -oo  = -oo  /\  A  e.  RR ) ) ) )
5 mnfxr 8694 . . 3  |- -oo  e.  RR*
6 rexr 7071 . . 3  |-  ( A  e.  RR  ->  A  e.  RR* )
7 ltxr 8695 . . 3  |-  ( ( -oo  e.  RR*  /\  A  e.  RR* )  ->  ( -oo  <  A  <->  ( (
( ( -oo  e.  RR  /\  A  e.  RR )  /\ -oo  <RR  A )  \/  ( -oo  = -oo  /\  A  = +oo ) )  \/  (
( -oo  e.  RR  /\  A  = +oo )  \/  ( -oo  = -oo  /\  A  e.  RR ) ) ) ) )
85, 6, 7sylancr 393 . 2  |-  ( A  e.  RR  ->  ( -oo  <  A  <->  ( (
( ( -oo  e.  RR  /\  A  e.  RR )  /\ -oo  <RR  A )  \/  ( -oo  = -oo  /\  A  = +oo ) )  \/  (
( -oo  e.  RR  /\  A  = +oo )  \/  ( -oo  = -oo  /\  A  e.  RR ) ) ) ) )
94, 8mpbird 156 1  |-  ( A  e.  RR  -> -oo  <  A )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 97    <-> wb 98    \/ wo 629    = wceq 1243    e. wcel 1393   class class class wbr 3764   RRcr 6888    <RR cltrr 6893   +oocpnf 7057   -oocmnf 7058   RR*cxr 7059    < clt 7060
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-13 1404  ax-14 1405  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022  ax-sep 3875  ax-pow 3927  ax-pr 3944  ax-un 4170  ax-cnex 6975
This theorem depends on definitions:  df-bi 110  df-3an 887  df-tru 1246  df-nf 1350  df-sb 1646  df-eu 1903  df-mo 1904  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-ral 2311  df-rex 2312  df-v 2559  df-un 2922  df-in 2924  df-ss 2931  df-pw 3361  df-sn 3381  df-pr 3382  df-op 3384  df-uni 3581  df-br 3765  df-opab 3819  df-xp 4351  df-pnf 7062  df-mnf 7063  df-xr 7064  df-ltxr 7065
This theorem is referenced by:  mnflt0  8705  mnfltxr  8707  xrlttr  8716  xrltso  8717  xrlttri3  8718  ngtmnft  8731  xrrebnd  8732  xrre3  8735  xltnegi  8748  elico2  8806  elicc2  8807  ioomax  8817  elioomnf  8837
  Copyright terms: Public domain W3C validator