Metamath Proof Explorer


Theorem volivth

Description: The Intermediate Value Theorem for the Lebesgue volume function. For any positive B <_ ( volA ) , there is a measurable subset of A whose volume is B . (Contributed by Mario Carneiro, 30-Aug-2014)

Ref Expression
Assertion volivth
|- ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )

Proof

Step Hyp Ref Expression
1 simpll
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> A e. dom vol )
2 mnfxr
 |-  -oo e. RR*
3 2 a1i
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> -oo e. RR* )
4 iccssxr
 |-  ( 0 [,] ( vol ` A ) ) C_ RR*
5 simpr
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> B e. ( 0 [,] ( vol ` A ) ) )
6 4 5 sseldi
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> B e. RR* )
7 6 adantr
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> B e. RR* )
8 iccssxr
 |-  ( 0 [,] +oo ) C_ RR*
9 volf
 |-  vol : dom vol --> ( 0 [,] +oo )
10 9 ffvelrni
 |-  ( A e. dom vol -> ( vol ` A ) e. ( 0 [,] +oo ) )
11 8 10 sseldi
 |-  ( A e. dom vol -> ( vol ` A ) e. RR* )
12 11 adantr
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> ( vol ` A ) e. RR* )
13 12 adantr
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> ( vol ` A ) e. RR* )
14 0xr
 |-  0 e. RR*
15 elicc1
 |-  ( ( 0 e. RR* /\ ( vol ` A ) e. RR* ) -> ( B e. ( 0 [,] ( vol ` A ) ) <-> ( B e. RR* /\ 0 <_ B /\ B <_ ( vol ` A ) ) ) )
16 14 12 15 sylancr
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> ( B e. ( 0 [,] ( vol ` A ) ) <-> ( B e. RR* /\ 0 <_ B /\ B <_ ( vol ` A ) ) ) )
17 5 16 mpbid
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> ( B e. RR* /\ 0 <_ B /\ B <_ ( vol ` A ) ) )
18 17 simp2d
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> 0 <_ B )
19 18 adantr
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> 0 <_ B )
20 mnflt0
 |-  -oo < 0
21 xrltletr
 |-  ( ( -oo e. RR* /\ 0 e. RR* /\ B e. RR* ) -> ( ( -oo < 0 /\ 0 <_ B ) -> -oo < B ) )
22 20 21 mpani
 |-  ( ( -oo e. RR* /\ 0 e. RR* /\ B e. RR* ) -> ( 0 <_ B -> -oo < B ) )
23 2 14 22 mp3an12
 |-  ( B e. RR* -> ( 0 <_ B -> -oo < B ) )
24 7 19 23 sylc
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> -oo < B )
25 simpr
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> B < ( vol ` A ) )
26 xrre2
 |-  ( ( ( -oo e. RR* /\ B e. RR* /\ ( vol ` A ) e. RR* ) /\ ( -oo < B /\ B < ( vol ` A ) ) ) -> B e. RR )
27 3 7 13 24 25 26 syl32anc
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> B e. RR )
28 volsup2
 |-  ( ( A e. dom vol /\ B e. RR /\ B < ( vol ` A ) ) -> E. n e. NN B < ( vol ` ( A i^i ( -u n [,] n ) ) ) )
29 1 27 25 28 syl3anc
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> E. n e. NN B < ( vol ` ( A i^i ( -u n [,] n ) ) ) )
30 nnre
 |-  ( n e. NN -> n e. RR )
31 30 ad2antrl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> n e. RR )
32 31 renegcld
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> -u n e. RR )
33 27 adantr
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> B e. RR )
34 0red
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> 0 e. RR )
35 nngt0
 |-  ( n e. NN -> 0 < n )
36 35 ad2antrl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> 0 < n )
37 31 lt0neg2d
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( 0 < n <-> -u n < 0 ) )
38 36 37 mpbid
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> -u n < 0 )
39 32 34 31 38 36 lttrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> -u n < n )
40 iccssre
 |-  ( ( -u n e. RR /\ n e. RR ) -> ( -u n [,] n ) C_ RR )
41 32 31 40 syl2anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( -u n [,] n ) C_ RR )
42 ax-resscn
 |-  RR C_ CC
43 ssid
 |-  CC C_ CC
44 cncfss
 |-  ( ( RR C_ CC /\ CC C_ CC ) -> ( RR -cn-> RR ) C_ ( RR -cn-> CC ) )
45 42 43 44 mp2an
 |-  ( RR -cn-> RR ) C_ ( RR -cn-> CC )
46 1 adantr
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> A e. dom vol )
47 eqid
 |-  ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) = ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) )
48 47 volcn
 |-  ( ( A e. dom vol /\ -u n e. RR ) -> ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) e. ( RR -cn-> RR ) )
49 46 32 48 syl2anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) e. ( RR -cn-> RR ) )
50 45 49 sseldi
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) e. ( RR -cn-> CC ) )
51 41 sselda
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ u e. ( -u n [,] n ) ) -> u e. RR )
52 cncff
 |-  ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) e. ( RR -cn-> RR ) -> ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) : RR --> RR )
53 49 52 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) : RR --> RR )
54 53 ffvelrnda
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ u e. RR ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` u ) e. RR )
55 51 54 syldan
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ u e. ( -u n [,] n ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` u ) e. RR )
56 oveq2
 |-  ( y = -u n -> ( -u n [,] y ) = ( -u n [,] -u n ) )
57 56 ineq2d
 |-  ( y = -u n -> ( A i^i ( -u n [,] y ) ) = ( A i^i ( -u n [,] -u n ) ) )
58 57 fveq2d
 |-  ( y = -u n -> ( vol ` ( A i^i ( -u n [,] y ) ) ) = ( vol ` ( A i^i ( -u n [,] -u n ) ) ) )
59 fvex
 |-  ( vol ` ( A i^i ( -u n [,] -u n ) ) ) e. _V
60 58 47 59 fvmpt
 |-  ( -u n e. RR -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` -u n ) = ( vol ` ( A i^i ( -u n [,] -u n ) ) ) )
61 32 60 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` -u n ) = ( vol ` ( A i^i ( -u n [,] -u n ) ) ) )
62 inss2
 |-  ( A i^i ( -u n [,] -u n ) ) C_ ( -u n [,] -u n )
63 32 rexrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> -u n e. RR* )
64 iccid
 |-  ( -u n e. RR* -> ( -u n [,] -u n ) = { -u n } )
65 63 64 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( -u n [,] -u n ) = { -u n } )
66 62 65 sseqtrid
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( A i^i ( -u n [,] -u n ) ) C_ { -u n } )
67 32 snssd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> { -u n } C_ RR )
68 66 67 sstrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( A i^i ( -u n [,] -u n ) ) C_ RR )
69 ovolsn
 |-  ( -u n e. RR -> ( vol* ` { -u n } ) = 0 )
70 32 69 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( vol* ` { -u n } ) = 0 )
71 ovolssnul
 |-  ( ( ( A i^i ( -u n [,] -u n ) ) C_ { -u n } /\ { -u n } C_ RR /\ ( vol* ` { -u n } ) = 0 ) -> ( vol* ` ( A i^i ( -u n [,] -u n ) ) ) = 0 )
72 66 67 70 71 syl3anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( vol* ` ( A i^i ( -u n [,] -u n ) ) ) = 0 )
73 nulmbl
 |-  ( ( ( A i^i ( -u n [,] -u n ) ) C_ RR /\ ( vol* ` ( A i^i ( -u n [,] -u n ) ) ) = 0 ) -> ( A i^i ( -u n [,] -u n ) ) e. dom vol )
74 68 72 73 syl2anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( A i^i ( -u n [,] -u n ) ) e. dom vol )
75 mblvol
 |-  ( ( A i^i ( -u n [,] -u n ) ) e. dom vol -> ( vol ` ( A i^i ( -u n [,] -u n ) ) ) = ( vol* ` ( A i^i ( -u n [,] -u n ) ) ) )
76 74 75 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( vol ` ( A i^i ( -u n [,] -u n ) ) ) = ( vol* ` ( A i^i ( -u n [,] -u n ) ) ) )
77 61 76 72 3eqtrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` -u n ) = 0 )
78 19 adantr
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> 0 <_ B )
79 77 78 eqbrtrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` -u n ) <_ B )
80 7 adantr
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> B e. RR* )
81 iccmbl
 |-  ( ( -u n e. RR /\ n e. RR ) -> ( -u n [,] n ) e. dom vol )
82 32 31 81 syl2anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( -u n [,] n ) e. dom vol )
83 inmbl
 |-  ( ( A e. dom vol /\ ( -u n [,] n ) e. dom vol ) -> ( A i^i ( -u n [,] n ) ) e. dom vol )
84 46 82 83 syl2anc
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( A i^i ( -u n [,] n ) ) e. dom vol )
85 9 ffvelrni
 |-  ( ( A i^i ( -u n [,] n ) ) e. dom vol -> ( vol ` ( A i^i ( -u n [,] n ) ) ) e. ( 0 [,] +oo ) )
86 8 85 sseldi
 |-  ( ( A i^i ( -u n [,] n ) ) e. dom vol -> ( vol ` ( A i^i ( -u n [,] n ) ) ) e. RR* )
87 84 86 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( vol ` ( A i^i ( -u n [,] n ) ) ) e. RR* )
88 simprr
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> B < ( vol ` ( A i^i ( -u n [,] n ) ) ) )
89 80 87 88 xrltled
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> B <_ ( vol ` ( A i^i ( -u n [,] n ) ) ) )
90 oveq2
 |-  ( y = n -> ( -u n [,] y ) = ( -u n [,] n ) )
91 90 ineq2d
 |-  ( y = n -> ( A i^i ( -u n [,] y ) ) = ( A i^i ( -u n [,] n ) ) )
92 91 fveq2d
 |-  ( y = n -> ( vol ` ( A i^i ( -u n [,] y ) ) ) = ( vol ` ( A i^i ( -u n [,] n ) ) ) )
93 fvex
 |-  ( vol ` ( A i^i ( -u n [,] n ) ) ) e. _V
94 92 47 93 fvmpt
 |-  ( n e. RR -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` n ) = ( vol ` ( A i^i ( -u n [,] n ) ) ) )
95 31 94 syl
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` n ) = ( vol ` ( A i^i ( -u n [,] n ) ) ) )
96 89 95 breqtrrd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> B <_ ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` n ) )
97 79 96 jca
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` -u n ) <_ B /\ B <_ ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` n ) ) )
98 32 31 33 39 41 50 55 97 ivthle
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> E. z e. ( -u n [,] n ) ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = B )
99 41 sselda
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ z e. ( -u n [,] n ) ) -> z e. RR )
100 oveq2
 |-  ( y = z -> ( -u n [,] y ) = ( -u n [,] z ) )
101 100 ineq2d
 |-  ( y = z -> ( A i^i ( -u n [,] y ) ) = ( A i^i ( -u n [,] z ) ) )
102 101 fveq2d
 |-  ( y = z -> ( vol ` ( A i^i ( -u n [,] y ) ) ) = ( vol ` ( A i^i ( -u n [,] z ) ) ) )
103 fvex
 |-  ( vol ` ( A i^i ( -u n [,] z ) ) ) e. _V
104 102 47 103 fvmpt
 |-  ( z e. RR -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = ( vol ` ( A i^i ( -u n [,] z ) ) ) )
105 99 104 syl
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ z e. ( -u n [,] n ) ) -> ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = ( vol ` ( A i^i ( -u n [,] z ) ) ) )
106 105 eqeq1d
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ z e. ( -u n [,] n ) ) -> ( ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = B <-> ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) )
107 46 adantr
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> A e. dom vol )
108 32 adantr
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> -u n e. RR )
109 99 adantrr
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> z e. RR )
110 iccmbl
 |-  ( ( -u n e. RR /\ z e. RR ) -> ( -u n [,] z ) e. dom vol )
111 108 109 110 syl2anc
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> ( -u n [,] z ) e. dom vol )
112 inmbl
 |-  ( ( A e. dom vol /\ ( -u n [,] z ) e. dom vol ) -> ( A i^i ( -u n [,] z ) ) e. dom vol )
113 107 111 112 syl2anc
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> ( A i^i ( -u n [,] z ) ) e. dom vol )
114 inss1
 |-  ( A i^i ( -u n [,] z ) ) C_ A
115 114 a1i
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> ( A i^i ( -u n [,] z ) ) C_ A )
116 simprr
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> ( vol ` ( A i^i ( -u n [,] z ) ) ) = B )
117 sseq1
 |-  ( x = ( A i^i ( -u n [,] z ) ) -> ( x C_ A <-> ( A i^i ( -u n [,] z ) ) C_ A ) )
118 fveqeq2
 |-  ( x = ( A i^i ( -u n [,] z ) ) -> ( ( vol ` x ) = B <-> ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) )
119 117 118 anbi12d
 |-  ( x = ( A i^i ( -u n [,] z ) ) -> ( ( x C_ A /\ ( vol ` x ) = B ) <-> ( ( A i^i ( -u n [,] z ) ) C_ A /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) )
120 119 rspcev
 |-  ( ( ( A i^i ( -u n [,] z ) ) e. dom vol /\ ( ( A i^i ( -u n [,] z ) ) C_ A /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
121 113 115 116 120 syl12anc
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ ( z e. ( -u n [,] n ) /\ ( vol ` ( A i^i ( -u n [,] z ) ) ) = B ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
122 121 expr
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ z e. ( -u n [,] n ) ) -> ( ( vol ` ( A i^i ( -u n [,] z ) ) ) = B -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) ) )
123 106 122 sylbid
 |-  ( ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) /\ z e. ( -u n [,] n ) ) -> ( ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = B -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) ) )
124 123 rexlimdva
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> ( E. z e. ( -u n [,] n ) ( ( y e. RR |-> ( vol ` ( A i^i ( -u n [,] y ) ) ) ) ` z ) = B -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) ) )
125 98 124 mpd
 |-  ( ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) /\ ( n e. NN /\ B < ( vol ` ( A i^i ( -u n [,] n ) ) ) ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
126 29 125 rexlimddv
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B < ( vol ` A ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
127 simpll
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B = ( vol ` A ) ) -> A e. dom vol )
128 ssid
 |-  A C_ A
129 128 a1i
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B = ( vol ` A ) ) -> A C_ A )
130 simpr
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B = ( vol ` A ) ) -> B = ( vol ` A ) )
131 130 eqcomd
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B = ( vol ` A ) ) -> ( vol ` A ) = B )
132 sseq1
 |-  ( x = A -> ( x C_ A <-> A C_ A ) )
133 fveqeq2
 |-  ( x = A -> ( ( vol ` x ) = B <-> ( vol ` A ) = B ) )
134 132 133 anbi12d
 |-  ( x = A -> ( ( x C_ A /\ ( vol ` x ) = B ) <-> ( A C_ A /\ ( vol ` A ) = B ) ) )
135 134 rspcev
 |-  ( ( A e. dom vol /\ ( A C_ A /\ ( vol ` A ) = B ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
136 127 129 131 135 syl12anc
 |-  ( ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) /\ B = ( vol ` A ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )
137 17 simp3d
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> B <_ ( vol ` A ) )
138 xrleloe
 |-  ( ( B e. RR* /\ ( vol ` A ) e. RR* ) -> ( B <_ ( vol ` A ) <-> ( B < ( vol ` A ) \/ B = ( vol ` A ) ) ) )
139 6 12 138 syl2anc
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> ( B <_ ( vol ` A ) <-> ( B < ( vol ` A ) \/ B = ( vol ` A ) ) ) )
140 137 139 mpbid
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> ( B < ( vol ` A ) \/ B = ( vol ` A ) ) )
141 126 136 140 mpjaodan
 |-  ( ( A e. dom vol /\ B e. ( 0 [,] ( vol ` A ) ) ) -> E. x e. dom vol ( x C_ A /\ ( vol ` x ) = B ) )