Theorem xaddnemnf 10259

Description: Closure of extended real addition in the subset RR* / { -oo }. (Contributed by Mario Carneiro, 20-Aug-2015.)

Assertion

Ref	Expression
xaddnemnf	|- ( ( ( A e. RR* /\ A =/= -oo ) /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) =/= -oo )

Proof of Theorem xaddnemnf

Step	Hyp	Ref	Expression
1		xrnemnf 10179	. 2 |- ( ( A e. RR* /\ A =/= -oo ) <-> ( A e. RR \/ A = +oo ) )
2		xrnemnf 10179	. . . 4 |- ( ( B e. RR* /\ B =/= -oo ) <-> ( B e. RR \/ B = +oo ) )
3		rexadd 10254	. . . . . . 7 |- ( ( A e. RR /\ B e. RR ) -> ( A +e B ) = ( A + B ) )
4		readdcl 8305	. . . . . . 7 |- ( ( A e. RR /\ B e. RR ) -> ( A + B ) e. RR )
5	3, 4	eqeltrd 2315	. . . . . 6 |- ( ( A e. RR /\ B e. RR ) -> ( A +e B ) e. RR )
6	5	renemnfd 8377	. . . . 5 |- ( ( A e. RR /\ B e. RR ) -> ( A +e B ) =/= -oo )
7		oveq2 6093	. . . . . . 7 |- ( B = +oo -> ( A +e B ) = ( A +e +oo ) )
8		rexr 8371	. . . . . . . 8 |- ( A e. RR -> A e. RR* )
9		renemnf 8374	. . . . . . . 8 |- ( A e. RR -> A =/= -oo )
10		xaddpnf1 10248	. . . . . . . 8 |- ( ( A e. RR* /\ A =/= -oo ) -> ( A +e +oo ) = +oo )
11	8, 9, 10	syl2anc 415	. . . . . . 7 |- ( A e. RR -> ( A +e +oo ) = +oo )
12	7, 11	sylan9eqr 2293	. . . . . 6 |- ( ( A e. RR /\ B = +oo ) -> ( A +e B ) = +oo )
13		pnfnemnf 8380	. . . . . . 7 |- +oo =/= -oo
14	13	a1i 9	. . . . . 6 |- ( ( A e. RR /\ B = +oo ) -> +oo =/= -oo )
15	12, 14	eqnetrd 2444	. . . . 5 |- ( ( A e. RR /\ B = +oo ) -> ( A +e B ) =/= -oo )
16	6, 15	jaodan 809	. . . 4 |- ( ( A e. RR /\ ( B e. RR \/ B = +oo ) ) -> ( A +e B ) =/= -oo )
17	2, 16	sylan2b 287	. . 3 |- ( ( A e. RR /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) =/= -oo )
18		oveq1 6092	. . . . 5 |- ( A = +oo -> ( A +e B ) = ( +oo +e B ) )
19		xaddpnf2 10249	. . . . 5 |- ( ( B e. RR* /\ B =/= -oo ) -> ( +oo +e B ) = +oo )
20	18, 19	sylan9eq 2291	. . . 4 |- ( ( A = +oo /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) = +oo )
21	13	a1i 9	. . . 4 |- ( ( A = +oo /\ ( B e. RR* /\ B =/= -oo ) ) -> +oo =/= -oo )
22	20, 21	eqnetrd 2444	. . 3 |- ( ( A = +oo /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) =/= -oo )
23	17, 22	jaoian 807	. 2 |- ( ( ( A e. RR \/ A = +oo ) /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) =/= -oo )
24	1, 23	sylanb 284	1 |- ( ( ( A e. RR* /\ A =/= -oo ) /\ ( B e. RR* /\ B =/= -oo ) ) -> ( A +e B ) =/= -oo )

This proof depends on syntax axioms:   -> wi 4   /\ wa 104   \/ wo 720   = wceq 1402   e. wcel 2209   =/= wne 2420  (class class class)co 6085   RRcr 8178   + caddc 8182   +oocpnf 8357   -oocmnf 8358   RR*cxr 8359   +ecxad 10172

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4249  ax-pow 4311  ax-pr 4346  ax-un 4578  ax-setind 4684  ax-cnex 8270  ax-resscn 8271  ax-1re 8273  ax-addrcl 8276  ax-rnegex 8288

This proof depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-rab 2537  df-v 2823  df-sbc 3052  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-if 3639  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-br 4131  df-opab 4193  df-id 4438  df-xp 4780  df-rel 4781  df-cnv 4782  df-co 4783  df-dm 4784  df-iota 5337  df-fun 5379  df-fv 5385  df-ov 6088  df-oprab 6089  df-mpo 6090  df-pnf 8362  df-mnf 8363  df-xr 8364  df-xadd 10175

This theorem is used by:  xaddass  10271  xlt2add  10282  xadd4d  10287  xleaddadd  10289