Theorem xnegneg 9790

Description: Extended real version of negneg 8169. (Contributed by Mario Carneiro, 20-Aug-2015.)

Assertion

Ref	Expression
xnegneg	|- ( A e. RR* -> -e -e A = A )

Proof of Theorem xnegneg

Step	Hyp	Ref	Expression
1		elxr 9733	. 2 |- ( A e. RR* <-> ( A e. RR \/ A = +oo \/ A = -oo ) )
2		rexneg 9787	. . . . 5 |- ( A e. RR -> -e A = -u A )
3		xnegeq 9784	. . . . 5 |- ( -e A = -u A -> -e -e A = -e -u A )
4	2, 3	syl 14	. . . 4 |- ( A e. RR -> -e -e A = -e -u A )
5		renegcl 8180	. . . . 5 |- ( A e. RR -> -u A e. RR )
6		rexneg 9787	. . . . 5 |- ( -u A e. RR -> -e -u A = -u -u A )
7	5, 6	syl 14	. . . 4 |- ( A e. RR -> -e -u A = -u -u A )
8		recn 7907	. . . . 5 |- ( A e. RR -> A e. CC )
9	8	negnegd 8221	. . . 4 |- ( A e. RR -> -u -u A = A )
10	4, 7, 9	3eqtrd 2207	. . 3 |- ( A e. RR -> -e -e A = A )
11		xnegmnf 9786	. . . 4 |- -e -oo = +oo
12		xnegeq 9784	. . . . . 6 |- ( A = +oo -> -e A = -e +oo )
13		xnegpnf 9785	. . . . . 6 |- -e +oo = -oo
14	12, 13	eqtrdi 2219	. . . . 5 |- ( A = +oo -> -e A = -oo )
15		xnegeq 9784	. . . . 5 |- ( -e A = -oo -> -e -e A = -e -oo )
16	14, 15	syl 14	. . . 4 |- ( A = +oo -> -e -e A = -e -oo )
17		id 19	. . . 4 |- ( A = +oo -> A = +oo )
18	11, 16, 17	3eqtr4a 2229	. . 3 |- ( A = +oo -> -e -e A = A )
19		xnegeq 9784	. . . . . 6 |- ( A = -oo -> -e A = -e -oo )
20	19, 11	eqtrdi 2219	. . . . 5 |- ( A = -oo -> -e A = +oo )
21		xnegeq 9784	. . . . 5 |- ( -e A = +oo -> -e -e A = -e +oo )
22	20, 21	syl 14	. . . 4 |- ( A = -oo -> -e -e A = -e +oo )
23		id 19	. . . 4 |- ( A = -oo -> A = -oo )
24	13, 22, 23	3eqtr4a 2229	. . 3 |- ( A = -oo -> -e -e A = A )
25	10, 18, 24	3jaoi 1298	. 2 |- ( ( A e. RR \/ A = +oo \/ A = -oo ) -> -e -e A = A )
26	1, 25	sylbi 120	1 |- ( A e. RR* -> -e -e A = A )

Syntax hints:   -> wi 4   \/ w3o 972   = wceq 1348   e. wcel 2141   RRcr 7773   +oocpnf 7951   -oocmnf 7952   RR*cxr 7953   -ucneg 8091   -ecxne 9726

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 609  ax-in2 610  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-13 2143  ax-14 2144  ax-ext 2152  ax-sep 4107  ax-pow 4160  ax-pr 4194  ax-un 4418  ax-setind 4521  ax-cnex 7865  ax-resscn 7866  ax-1cn 7867  ax-icn 7869  ax-addcl 7870  ax-addrcl 7871  ax-mulcl 7872  ax-addcom 7874  ax-addass 7876  ax-distr 7878  ax-i2m1 7879  ax-0id 7882  ax-rnegex 7883  ax-cnre 7885

This theorem depends on definitions:  df-bi 116  df-3or 974  df-3an 975  df-tru 1351  df-fal 1354  df-nf 1454  df-sb 1756  df-eu 2022  df-mo 2023  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-ne 2341  df-nel 2436  df-ral 2453  df-rex 2454  df-reu 2455  df-rab 2457  df-v 2732  df-sbc 2956  df-dif 3123  df-un 3125  df-in 3127  df-ss 3134  df-if 3527  df-pw 3568  df-sn 3589  df-pr 3590  df-op 3592  df-uni 3797  df-br 3990  df-opab 4051  df-id 4278  df-xp 4617  df-rel 4618  df-cnv 4619  df-co 4620  df-dm 4621  df-iota 5160  df-fun 5200  df-fv 5206  df-riota 5809  df-ov 5856  df-oprab 5857  df-mpo 5858  df-pnf 7956  df-mnf 7957  df-xr 7958  df-sub 8092  df-neg 8093  df-xneg 9729

This theorem is referenced by:  xneg11  9791  xltneg  9793  xnegdi  9825  xnpcan  9829  xrnegiso  11225  infxrnegsupex  11226  xrnegcon1d  11227  xrminmax  11228  xrmin1inf  11230  xrmin2inf  11231  xrltmininf  11233  xrlemininf  11234  xrminltinf  11235  xrminadd  11238