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Theorem xaddpnf1 9597
Description: Addition of positive infinity on the right. (Contributed by Mario Carneiro, 20-Aug-2015.)
Assertion
Ref Expression
xaddpnf1  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  ->  ( A +e +oo )  = +oo )

Proof of Theorem xaddpnf1
StepHypRef Expression
1 pnfxr 7786 . . . 4  |- +oo  e.  RR*
2 xaddval 9596 . . . 4  |-  ( ( A  e.  RR*  /\ +oo  e.  RR* )  ->  ( A +e +oo )  =  if ( A  = +oo ,  if ( +oo  = -oo , 
0 , +oo ) ,  if ( A  = -oo ,  if ( +oo  = +oo , 
0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) ) ) )
31, 2mpan2 421 . . 3  |-  ( A  e.  RR*  ->  ( A +e +oo )  =  if ( A  = +oo ,  if ( +oo  = -oo , 
0 , +oo ) ,  if ( A  = -oo ,  if ( +oo  = +oo , 
0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) ) ) )
43adantr 274 . 2  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  ->  ( A +e +oo )  =  if ( A  = +oo ,  if ( +oo  = -oo , 
0 , +oo ) ,  if ( A  = -oo ,  if ( +oo  = +oo , 
0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) ) ) )
5 pnfnemnf 7788 . . . . 5  |- +oo  =/= -oo
6 ifnefalse 3455 . . . . 5  |-  ( +oo  =/= -oo  ->  if ( +oo  = -oo ,  0 , +oo )  = +oo )
75, 6mp1i 10 . . . 4  |-  ( A  =/= -oo  ->  if ( +oo  = -oo , 
0 , +oo )  = +oo )
8 ifnefalse 3455 . . . . 5  |-  ( A  =/= -oo  ->  if ( A  = -oo ,  if ( +oo  = +oo ,  0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo )
) ) )  =  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) )
9 eqid 2117 . . . . . 6  |- +oo  = +oo
109iftruei 3450 . . . . 5  |-  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo , 
( A  + +oo ) ) )  = +oo
118, 10syl6eq 2166 . . . 4  |-  ( A  =/= -oo  ->  if ( A  = -oo ,  if ( +oo  = +oo ,  0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo )
) ) )  = +oo )
127, 11ifeq12d 3461 . . 3  |-  ( A  =/= -oo  ->  if ( A  = +oo ,  if ( +oo  = -oo ,  0 , +oo ) ,  if ( A  = -oo ,  if ( +oo  = +oo , 
0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) ) )  =  if ( A  = +oo , +oo , +oo ) )
13 xrpnfdc 9593 . . . 4  |-  ( A  e.  RR*  -> DECID  A  = +oo )
14 ifiddc 3475 . . . 4  |-  (DECID  A  = +oo  ->  if ( A  = +oo , +oo , +oo )  = +oo )
1513, 14syl 14 . . 3  |-  ( A  e.  RR*  ->  if ( A  = +oo , +oo , +oo )  = +oo )
1612, 15sylan9eqr 2172 . 2  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  ->  if ( A  = +oo ,  if ( +oo  = -oo ,  0 , +oo ) ,  if ( A  = -oo ,  if ( +oo  = +oo , 
0 , -oo ) ,  if ( +oo  = +oo , +oo ,  if ( +oo  = -oo , -oo ,  ( A  + +oo ) ) ) ) )  = +oo )
174, 16eqtrd 2150 1  |-  ( ( A  e.  RR*  /\  A  =/= -oo )  ->  ( A +e +oo )  = +oo )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103  DECID wdc 804    = wceq 1316    e. wcel 1465    =/= wne 2285   ifcif 3444  (class class class)co 5742   0cc0 7588    + caddc 7591   +oocpnf 7765   -oocmnf 7766   RR*cxr 7767   +ecxad 9525
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 588  ax-in2 589  ax-io 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-13 1476  ax-14 1477  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099  ax-sep 4016  ax-pow 4068  ax-pr 4101  ax-un 4325  ax-setind 4422  ax-cnex 7679  ax-resscn 7680  ax-1re 7682  ax-addrcl 7685  ax-rnegex 7697
This theorem depends on definitions:  df-bi 116  df-dc 805  df-3or 948  df-3an 949  df-tru 1319  df-fal 1322  df-nf 1422  df-sb 1721  df-eu 1980  df-mo 1981  df-clab 2104  df-cleq 2110  df-clel 2113  df-nfc 2247  df-ne 2286  df-nel 2381  df-ral 2398  df-rex 2399  df-rab 2402  df-v 2662  df-sbc 2883  df-dif 3043  df-un 3045  df-in 3047  df-ss 3054  df-if 3445  df-pw 3482  df-sn 3503  df-pr 3504  df-op 3506  df-uni 3707  df-br 3900  df-opab 3960  df-id 4185  df-xp 4515  df-rel 4516  df-cnv 4517  df-co 4518  df-dm 4519  df-iota 5058  df-fun 5095  df-fv 5101  df-ov 5745  df-oprab 5746  df-mpo 5747  df-pnf 7770  df-mnf 7771  df-xr 7772  df-xadd 9528
This theorem is referenced by:  xaddnemnf  9608  xaddcom  9612  xnn0xadd0  9618  xnegdi  9619  xaddass  9620  xleadd1a  9624  xlt2add  9631  xsubge0  9632  xposdif  9633  xlesubadd  9634  xrbdtri  11013  isxmet2d  12444
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