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Theorem xnegneg 10129
Description: Extended real version of negneg 8488. (Contributed by Mario Carneiro, 20-Aug-2015.)
Assertion
Ref Expression
xnegneg  |-  ( A  e.  RR*  ->  -e  -e A  =  A )

Proof of Theorem xnegneg
StepHypRef Expression
1 elxr 10072 . 2  |-  ( A  e.  RR*  <->  ( A  e.  RR  \/  A  = +oo  \/  A  = -oo ) )
2 rexneg 10126 . . . . 5  |-  ( A  e.  RR  ->  -e
A  =  -u A
)
3 xnegeq 10123 . . . . 5  |-  (  -e A  =  -u A  -> 
-e  -e
A  =  -e -u A )
42, 3syl 14 . . . 4  |-  ( A  e.  RR  ->  -e  -e A  =  -e -u A )
5 renegcl 8499 . . . . 5  |-  ( A  e.  RR  ->  -u A  e.  RR )
6 rexneg 10126 . . . . 5  |-  ( -u A  e.  RR  ->  -e -u A  =  -u -u A )
75, 6syl 14 . . . 4  |-  ( A  e.  RR  ->  -e -u A  =  -u -u A
)
8 recn 8225 . . . . 5  |-  ( A  e.  RR  ->  A  e.  CC )
98negnegd 8540 . . . 4  |-  ( A  e.  RR  ->  -u -u A  =  A )
104, 7, 93eqtrd 2268 . . 3  |-  ( A  e.  RR  ->  -e  -e A  =  A )
11 xnegmnf 10125 . . . 4  |-  -e -oo  = +oo
12 xnegeq 10123 . . . . . 6  |-  ( A  = +oo  ->  -e
A  =  -e +oo )
13 xnegpnf 10124 . . . . . 6  |-  -e +oo  = -oo
1412, 13eqtrdi 2280 . . . . 5  |-  ( A  = +oo  ->  -e
A  = -oo )
15 xnegeq 10123 . . . . 5  |-  (  -e A  = -oo  -> 
-e  -e
A  =  -e -oo )
1614, 15syl 14 . . . 4  |-  ( A  = +oo  ->  -e  -e A  =  -e -oo )
17 id 19 . . . 4  |-  ( A  = +oo  ->  A  = +oo )
1811, 16, 173eqtr4a 2290 . . 3  |-  ( A  = +oo  ->  -e  -e A  =  A )
19 xnegeq 10123 . . . . . 6  |-  ( A  = -oo  ->  -e
A  =  -e -oo )
2019, 11eqtrdi 2280 . . . . 5  |-  ( A  = -oo  ->  -e
A  = +oo )
21 xnegeq 10123 . . . . 5  |-  (  -e A  = +oo  -> 
-e  -e
A  =  -e +oo )
2220, 21syl 14 . . . 4  |-  ( A  = -oo  ->  -e  -e A  =  -e +oo )
23 id 19 . . . 4  |-  ( A  = -oo  ->  A  = -oo )
2413, 22, 233eqtr4a 2290 . . 3  |-  ( A  = -oo  ->  -e  -e A  =  A )
2510, 18, 243jaoi 1340 . 2  |-  ( ( A  e.  RR  \/  A  = +oo  \/  A  = -oo )  ->  -e  -e A  =  A )
261, 25sylbi 121 1  |-  ( A  e.  RR*  ->  -e  -e A  =  A )
Colors of variables: wff set class
Syntax hints:    -> wi 4    \/ w3o 1004    = wceq 1398    e. wcel 2202   RRcr 8091   +oocpnf 8270   -oocmnf 8271   RR*cxr 8272   -ucneg 8410    -ecxne 10065
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 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2204  ax-14 2205  ax-ext 2213  ax-sep 4212  ax-pow 4270  ax-pr 4305  ax-un 4536  ax-setind 4641  ax-cnex 8183  ax-resscn 8184  ax-1cn 8185  ax-icn 8187  ax-addcl 8188  ax-addrcl 8189  ax-mulcl 8190  ax-addcom 8192  ax-addass 8194  ax-distr 8196  ax-i2m1 8197  ax-0id 8200  ax-rnegex 8201  ax-cnre 8203
This theorem depends on definitions:  df-bi 117  df-3or 1006  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1811  df-eu 2082  df-mo 2083  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ne 2404  df-nel 2499  df-ral 2516  df-rex 2517  df-reu 2518  df-rab 2520  df-v 2805  df-sbc 3033  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-if 3608  df-pw 3658  df-sn 3679  df-pr 3680  df-op 3682  df-uni 3899  df-br 4094  df-opab 4156  df-id 4396  df-xp 4737  df-rel 4738  df-cnv 4739  df-co 4740  df-dm 4741  df-iota 5293  df-fun 5335  df-fv 5341  df-riota 5981  df-ov 6031  df-oprab 6032  df-mpo 6033  df-pnf 8275  df-mnf 8276  df-xr 8277  df-sub 8411  df-neg 8412  df-xneg 10068
This theorem is referenced by:  xneg11  10130  xltneg  10132  xnegdi  10164  xnpcan  10168  xrnegiso  11902  infxrnegsupex  11903  xrnegcon1d  11904  xrminmax  11905  xrmin1inf  11907  xrmin2inf  11908  xrltmininf  11910  xrlemininf  11911  xrminltinf  11912  xrminadd  11915
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