Metamath Proof Explorer


Theorem esumlub

Description: The extended sum is the lowest upper bound for the partial sums. (Contributed by Thierry Arnoux, 19-Oct-2017) (Proof shortened by AV, 12-Dec-2019)

Ref Expression
Hypotheses esumlub.f
|- F/ k ph
esumlub.0
|- ( ph -> A e. V )
esumlub.1
|- ( ( ph /\ k e. A ) -> B e. ( 0 [,] +oo ) )
esumlub.2
|- ( ph -> X e. RR* )
esumlub.3
|- ( ph -> X < sum* k e. A B )
Assertion esumlub
|- ( ph -> E. a e. ( ~P A i^i Fin ) X < sum* k e. a B )

Proof

Step Hyp Ref Expression
1 esumlub.f
 |-  F/ k ph
2 esumlub.0
 |-  ( ph -> A e. V )
3 esumlub.1
 |-  ( ( ph /\ k e. A ) -> B e. ( 0 [,] +oo ) )
4 esumlub.2
 |-  ( ph -> X e. RR* )
5 esumlub.3
 |-  ( ph -> X < sum* k e. A B )
6 nfcv
 |-  F/_ k A
7 eqidd
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) )
8 1 6 2 3 7 esumval
 |-  ( ph -> sum* k e. A B = sup ( ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) , RR* , < ) )
9 8 breq2d
 |-  ( ph -> ( X < sum* k e. A B <-> X < sup ( ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) , RR* , < ) ) )
10 iccssxr
 |-  ( 0 [,] +oo ) C_ RR*
11 xrge0base
 |-  ( 0 [,] +oo ) = ( Base ` ( RR*s |`s ( 0 [,] +oo ) ) )
12 xrge0cmn
 |-  ( RR*s |`s ( 0 [,] +oo ) ) e. CMnd
13 12 a1i
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> ( RR*s |`s ( 0 [,] +oo ) ) e. CMnd )
14 inss2
 |-  ( ~P A i^i Fin ) C_ Fin
15 simpr
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> x e. ( ~P A i^i Fin ) )
16 14 15 sseldi
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> x e. Fin )
17 nfv
 |-  F/ k x e. ( ~P A i^i Fin )
18 1 17 nfan
 |-  F/ k ( ph /\ x e. ( ~P A i^i Fin ) )
19 simpll
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> ph )
20 inss1
 |-  ( ~P A i^i Fin ) C_ ~P A
21 20 sseli
 |-  ( x e. ( ~P A i^i Fin ) -> x e. ~P A )
22 21 ad2antlr
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> x e. ~P A )
23 22 elpwid
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> x C_ A )
24 simpr
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> k e. x )
25 23 24 sseldd
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> k e. A )
26 19 25 3 syl2anc
 |-  ( ( ( ph /\ x e. ( ~P A i^i Fin ) ) /\ k e. x ) -> B e. ( 0 [,] +oo ) )
27 26 ex
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> ( k e. x -> B e. ( 0 [,] +oo ) ) )
28 18 27 ralrimi
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> A. k e. x B e. ( 0 [,] +oo ) )
29 11 13 16 28 gsummptcl
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) e. ( 0 [,] +oo ) )
30 10 29 sseldi
 |-  ( ( ph /\ x e. ( ~P A i^i Fin ) ) -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) e. RR* )
31 30 ralrimiva
 |-  ( ph -> A. x e. ( ~P A i^i Fin ) ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) e. RR* )
32 eqid
 |-  ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) = ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) )
33 32 rnmptss
 |-  ( A. x e. ( ~P A i^i Fin ) ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) e. RR* -> ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) C_ RR* )
34 31 33 syl
 |-  ( ph -> ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) C_ RR* )
35 supxrlub
 |-  ( ( ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) C_ RR* /\ X e. RR* ) -> ( X < sup ( ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) , RR* , < ) <-> E. y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) X < y ) )
36 34 4 35 syl2anc
 |-  ( ph -> ( X < sup ( ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) , RR* , < ) <-> E. y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) X < y ) )
37 9 36 bitrd
 |-  ( ph -> ( X < sum* k e. A B <-> E. y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) X < y ) )
38 5 37 mpbid
 |-  ( ph -> E. y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) X < y )
39 ovex
 |-  ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) e. _V
40 39 a1i
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) e. _V )
41 mpteq1
 |-  ( x = a -> ( k e. x |-> B ) = ( k e. a |-> B ) )
42 41 oveq2d
 |-  ( x = a -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) )
43 42 cbvmptv
 |-  ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) = ( a e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) )
44 43 39 elrnmpti
 |-  ( y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) <-> E. a e. ( ~P A i^i Fin ) y = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) )
45 44 a1i
 |-  ( ph -> ( y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) <-> E. a e. ( ~P A i^i Fin ) y = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) ) )
46 simpr
 |-  ( ( ph /\ y = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) ) -> y = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) )
47 46 breq2d
 |-  ( ( ph /\ y = ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) ) -> ( X < y <-> X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) ) )
48 40 45 47 rexxfr2d
 |-  ( ph -> ( E. y e. ran ( x e. ( ~P A i^i Fin ) |-> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. x |-> B ) ) ) X < y <-> E. a e. ( ~P A i^i Fin ) X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) ) )
49 38 48 mpbid
 |-  ( ph -> E. a e. ( ~P A i^i Fin ) X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) )
50 nfv
 |-  F/ k a e. ( ~P A i^i Fin )
51 1 50 nfan
 |-  F/ k ( ph /\ a e. ( ~P A i^i Fin ) )
52 simpr
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> a e. ( ~P A i^i Fin ) )
53 14 52 sseldi
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> a e. Fin )
54 simpll
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> ph )
55 20 sseli
 |-  ( a e. ( ~P A i^i Fin ) -> a e. ~P A )
56 55 ad2antlr
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> a e. ~P A )
57 56 elpwid
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> a C_ A )
58 simpr
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> k e. a )
59 57 58 sseldd
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> k e. A )
60 54 59 3 syl2anc
 |-  ( ( ( ph /\ a e. ( ~P A i^i Fin ) ) /\ k e. a ) -> B e. ( 0 [,] +oo ) )
61 51 53 60 gsumesum
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) = sum* k e. a B )
62 61 breq2d
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> ( X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) <-> X < sum* k e. a B ) )
63 62 biimpd
 |-  ( ( ph /\ a e. ( ~P A i^i Fin ) ) -> ( X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) -> X < sum* k e. a B ) )
64 63 reximdva
 |-  ( ph -> ( E. a e. ( ~P A i^i Fin ) X < ( ( RR*s |`s ( 0 [,] +oo ) ) gsum ( k e. a |-> B ) ) -> E. a e. ( ~P A i^i Fin ) X < sum* k e. a B ) )
65 49 64 mpd
 |-  ( ph -> E. a e. ( ~P A i^i Fin ) X < sum* k e. a B )