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Theorem mbfsub 19554
Description: The difference of two measurable functions is measurable. (Contributed by Mario Carneiro, 5-Sep-2014.)
Hypotheses
Ref Expression
mbfadd.1  |-  ( ph  ->  F  e. MblFn )
mbfadd.2  |-  ( ph  ->  G  e. MblFn )
Assertion
Ref Expression
mbfsub  |-  ( ph  ->  ( F  o F  -  G )  e. MblFn
)

Proof of Theorem mbfsub
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 mbfadd.1 . . . . . . . 8  |-  ( ph  ->  F  e. MblFn )
2 mbff 19519 . . . . . . . 8  |-  ( F  e. MblFn  ->  F : dom  F --> CC )
31, 2syl 16 . . . . . . 7  |-  ( ph  ->  F : dom  F --> CC )
4 elin 3530 . . . . . . . 8  |-  ( x  e.  ( dom  F  i^i  dom  G )  <->  ( x  e.  dom  F  /\  x  e.  dom  G ) )
54simplbi 447 . . . . . . 7  |-  ( x  e.  ( dom  F  i^i  dom  G )  ->  x  e.  dom  F )
6 ffvelrn 5868 . . . . . . 7  |-  ( ( F : dom  F --> CC  /\  x  e.  dom  F )  ->  ( F `  x )  e.  CC )
73, 5, 6syl2an 464 . . . . . 6  |-  ( (
ph  /\  x  e.  ( dom  F  i^i  dom  G ) )  ->  ( F `  x )  e.  CC )
8 mbfadd.2 . . . . . . . 8  |-  ( ph  ->  G  e. MblFn )
9 mbff 19519 . . . . . . . 8  |-  ( G  e. MblFn  ->  G : dom  G --> CC )
108, 9syl 16 . . . . . . 7  |-  ( ph  ->  G : dom  G --> CC )
114simprbi 451 . . . . . . 7  |-  ( x  e.  ( dom  F  i^i  dom  G )  ->  x  e.  dom  G )
12 ffvelrn 5868 . . . . . . 7  |-  ( ( G : dom  G --> CC  /\  x  e.  dom  G )  ->  ( G `  x )  e.  CC )
1310, 11, 12syl2an 464 . . . . . 6  |-  ( (
ph  /\  x  e.  ( dom  F  i^i  dom  G ) )  ->  ( G `  x )  e.  CC )
147, 13negsubd 9417 . . . . 5  |-  ( (
ph  /\  x  e.  ( dom  F  i^i  dom  G ) )  ->  (
( F `  x
)  +  -u ( G `  x )
)  =  ( ( F `  x )  -  ( G `  x ) ) )
1514eqcomd 2441 . . . 4  |-  ( (
ph  /\  x  e.  ( dom  F  i^i  dom  G ) )  ->  (
( F `  x
)  -  ( G `
 x ) )  =  ( ( F `
 x )  + 
-u ( G `  x ) ) )
1615mpteq2dva 4295 . . 3  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( ( F `
 x )  -  ( G `  x ) ) )  =  ( x  e.  ( dom 
F  i^i  dom  G ) 
|->  ( ( F `  x )  +  -u ( G `  x ) ) ) )
17 ffn 5591 . . . . 5  |-  ( F : dom  F --> CC  ->  F  Fn  dom  F )
183, 17syl 16 . . . 4  |-  ( ph  ->  F  Fn  dom  F
)
19 ffn 5591 . . . . 5  |-  ( G : dom  G --> CC  ->  G  Fn  dom  G )
2010, 19syl 16 . . . 4  |-  ( ph  ->  G  Fn  dom  G
)
21 mbfdm 19520 . . . . 5  |-  ( F  e. MblFn  ->  dom  F  e.  dom  vol )
221, 21syl 16 . . . 4  |-  ( ph  ->  dom  F  e.  dom  vol )
23 mbfdm 19520 . . . . 5  |-  ( G  e. MblFn  ->  dom  G  e.  dom  vol )
248, 23syl 16 . . . 4  |-  ( ph  ->  dom  G  e.  dom  vol )
25 eqid 2436 . . . 4  |-  ( dom 
F  i^i  dom  G )  =  ( dom  F  i^i  dom  G )
26 eqidd 2437 . . . 4  |-  ( (
ph  /\  x  e.  dom  F )  ->  ( F `  x )  =  ( F `  x ) )
27 eqidd 2437 . . . 4  |-  ( (
ph  /\  x  e.  dom  G )  ->  ( G `  x )  =  ( G `  x ) )
2818, 20, 22, 24, 25, 26, 27offval 6312 . . 3  |-  ( ph  ->  ( F  o F  -  G )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( ( F `
 x )  -  ( G `  x ) ) ) )
29 inmbl 19436 . . . . 5  |-  ( ( dom  F  e.  dom  vol 
/\  dom  G  e.  dom  vol )  ->  ( dom  F  i^i  dom  G
)  e.  dom  vol )
3022, 24, 29syl2anc 643 . . . 4  |-  ( ph  ->  ( dom  F  i^i  dom 
G )  e.  dom  vol )
3113negcld 9398 . . . 4  |-  ( (
ph  /\  x  e.  ( dom  F  i^i  dom  G ) )  ->  -u ( G `  x )  e.  CC )
32 eqidd 2437 . . . 4  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( F `  x ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( F `  x ) ) )
33 eqidd 2437 . . . 4  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  -u ( G `  x ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  -u ( G `  x ) ) )
3430, 7, 31, 32, 33offval2 6322 . . 3  |-  ( ph  ->  ( ( x  e.  ( dom  F  i^i  dom 
G )  |->  ( F `
 x ) )  o F  +  ( x  e.  ( dom 
F  i^i  dom  G ) 
|->  -u ( G `  x ) ) )  =  ( x  e.  ( dom  F  i^i  dom 
G )  |->  ( ( F `  x )  +  -u ( G `  x ) ) ) )
3516, 28, 343eqtr4d 2478 . 2  |-  ( ph  ->  ( F  o F  -  G )  =  ( ( x  e.  ( dom  F  i^i  dom 
G )  |->  ( F `
 x ) )  o F  +  ( x  e.  ( dom 
F  i^i  dom  G ) 
|->  -u ( G `  x ) ) ) )
36 inss1 3561 . . . . 5  |-  ( dom 
F  i^i  dom  G ) 
C_  dom  F
37 resmpt 5191 . . . . 5  |-  ( ( dom  F  i^i  dom  G )  C_  dom  F  -> 
( ( x  e. 
dom  F  |->  ( F `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( F `  x ) ) )
3836, 37mp1i 12 . . . 4  |-  ( ph  ->  ( ( x  e. 
dom  F  |->  ( F `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( F `  x ) ) )
393feqmptd 5779 . . . . . 6  |-  ( ph  ->  F  =  ( x  e.  dom  F  |->  ( F `  x ) ) )
4039, 1eqeltrrd 2511 . . . . 5  |-  ( ph  ->  ( x  e.  dom  F 
|->  ( F `  x
) )  e. MblFn )
41 mbfres 19536 . . . . 5  |-  ( ( ( x  e.  dom  F 
|->  ( F `  x
) )  e. MblFn  /\  ( dom  F  i^i  dom  G
)  e.  dom  vol )  ->  ( ( x  e.  dom  F  |->  ( F `  x ) )  |`  ( dom  F  i^i  dom  G )
)  e. MblFn )
4240, 30, 41syl2anc 643 . . . 4  |-  ( ph  ->  ( ( x  e. 
dom  F  |->  ( F `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  e. MblFn
)
4338, 42eqeltrrd 2511 . . 3  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( F `  x ) )  e. MblFn
)
44 inss2 3562 . . . . . 6  |-  ( dom 
F  i^i  dom  G ) 
C_  dom  G
45 resmpt 5191 . . . . . 6  |-  ( ( dom  F  i^i  dom  G )  C_  dom  G  -> 
( ( x  e. 
dom  G  |->  ( G `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( G `  x ) ) )
4644, 45mp1i 12 . . . . 5  |-  ( ph  ->  ( ( x  e. 
dom  G  |->  ( G `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  =  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( G `  x ) ) )
4710feqmptd 5779 . . . . . . 7  |-  ( ph  ->  G  =  ( x  e.  dom  G  |->  ( G `  x ) ) )
4847, 8eqeltrrd 2511 . . . . . 6  |-  ( ph  ->  ( x  e.  dom  G 
|->  ( G `  x
) )  e. MblFn )
49 mbfres 19536 . . . . . 6  |-  ( ( ( x  e.  dom  G 
|->  ( G `  x
) )  e. MblFn  /\  ( dom  F  i^i  dom  G
)  e.  dom  vol )  ->  ( ( x  e.  dom  G  |->  ( G `  x ) )  |`  ( dom  F  i^i  dom  G )
)  e. MblFn )
5048, 30, 49syl2anc 643 . . . . 5  |-  ( ph  ->  ( ( x  e. 
dom  G  |->  ( G `
 x ) )  |`  ( dom  F  i^i  dom 
G ) )  e. MblFn
)
5146, 50eqeltrrd 2511 . . . 4  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  ( G `  x ) )  e. MblFn
)
5213, 51mbfneg 19542 . . 3  |-  ( ph  ->  ( x  e.  ( dom  F  i^i  dom  G )  |->  -u ( G `  x ) )  e. MblFn
)
5343, 52mbfadd 19553 . 2  |-  ( ph  ->  ( ( x  e.  ( dom  F  i^i  dom 
G )  |->  ( F `
 x ) )  o F  +  ( x  e.  ( dom 
F  i^i  dom  G ) 
|->  -u ( G `  x ) ) )  e. MblFn )
5435, 53eqeltrd 2510 1  |-  ( ph  ->  ( F  o F  -  G )  e. MblFn
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 359    = wceq 1652    e. wcel 1725    i^i cin 3319    C_ wss 3320    e. cmpt 4266   dom cdm 4878    |` cres 4880    Fn wfn 5449   -->wf 5450   ` cfv 5454  (class class class)co 6081    o Fcof 6303   CCcc 8988    + caddc 8993    - cmin 9291   -ucneg 9292   volcvol 19360  MblFncmbf 19506
This theorem is referenced by:  mbfmul  19618  iblulm  20323
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1555  ax-5 1566  ax-17 1626  ax-9 1666  ax-8 1687  ax-13 1727  ax-14 1729  ax-6 1744  ax-7 1749  ax-11 1761  ax-12 1950  ax-ext 2417  ax-rep 4320  ax-sep 4330  ax-nul 4338  ax-pow 4377  ax-pr 4403  ax-un 4701  ax-inf2 7596  ax-cc 8315  ax-cnex 9046  ax-resscn 9047  ax-1cn 9048  ax-icn 9049  ax-addcl 9050  ax-addrcl 9051  ax-mulcl 9052  ax-mulrcl 9053  ax-mulcom 9054  ax-addass 9055  ax-mulass 9056  ax-distr 9057  ax-i2m1 9058  ax-1ne0 9059  ax-1rid 9060  ax-rnegex 9061  ax-rrecex 9062  ax-cnre 9063  ax-pre-lttri 9064  ax-pre-lttrn 9065  ax-pre-ltadd 9066  ax-pre-mulgt0 9067  ax-pre-sup 9068
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3or 937  df-3an 938  df-tru 1328  df-ex 1551  df-nf 1554  df-sb 1659  df-eu 2285  df-mo 2286  df-clab 2423  df-cleq 2429  df-clel 2432  df-nfc 2561  df-ne 2601  df-nel 2602  df-ral 2710  df-rex 2711  df-reu 2712  df-rmo 2713  df-rab 2714  df-v 2958  df-sbc 3162  df-csb 3252  df-dif 3323  df-un 3325  df-in 3327  df-ss 3334  df-pss 3336  df-nul 3629  df-if 3740  df-pw 3801  df-sn 3820  df-pr 3821  df-tp 3822  df-op 3823  df-uni 4016  df-int 4051  df-iun 4095  df-disj 4183  df-br 4213  df-opab 4267  df-mpt 4268  df-tr 4303  df-eprel 4494  df-id 4498  df-po 4503  df-so 4504  df-fr 4541  df-se 4542  df-we 4543  df-ord 4584  df-on 4585  df-lim 4586  df-suc 4587  df-om 4846  df-xp 4884  df-rel 4885  df-cnv 4886  df-co 4887  df-dm 4888  df-rn 4889  df-res 4890  df-ima 4891  df-iota 5418  df-fun 5456  df-fn 5457  df-f 5458  df-f1 5459  df-fo 5460  df-f1o 5461  df-fv 5462  df-isom 5463  df-ov 6084  df-oprab 6085  df-mpt2 6086  df-of 6305  df-1st 6349  df-2nd 6350  df-riota 6549  df-recs 6633  df-rdg 6668  df-1o 6724  df-2o 6725  df-oadd 6728  df-omul 6729  df-er 6905  df-map 7020  df-pm 7021  df-en 7110  df-dom 7111  df-sdom 7112  df-fin 7113  df-sup 7446  df-oi 7479  df-card 7826  df-acn 7829  df-cda 8048  df-pnf 9122  df-mnf 9123  df-xr 9124  df-ltxr 9125  df-le 9126  df-sub 9293  df-neg 9294  df-div 9678  df-nn 10001  df-2 10058  df-3 10059  df-n0 10222  df-z 10283  df-uz 10489  df-q 10575  df-rp 10613  df-xadd 10711  df-ioo 10920  df-ioc 10921  df-ico 10922  df-icc 10923  df-fz 11044  df-fzo 11136  df-fl 11202  df-seq 11324  df-exp 11383  df-hash 11619  df-cj 11904  df-re 11905  df-im 11906  df-sqr 12040  df-abs 12041  df-clim 12282  df-rlim 12283  df-sum 12480  df-xmet 16695  df-met 16696  df-ovol 19361  df-vol 19362  df-mbf 19512
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