Metamath Proof Explorer


Theorem esumsnf

Description: The extended sum of a singleton is the term. (Contributed by Thierry Arnoux, 2-Jan-2017) (Revised by Thierry Arnoux, 2-May-2020)

Ref Expression
Hypotheses esumsnf.0 𝑘 𝐵
esumsnf.1 ( ( 𝜑𝑘 = 𝑀 ) → 𝐴 = 𝐵 )
esumsnf.2 ( 𝜑𝑀𝑉 )
esumsnf.3 ( 𝜑𝐵 ∈ ( 0 [,] +∞ ) )
Assertion esumsnf ( 𝜑 → Σ* 𝑘 ∈ { 𝑀 } 𝐴 = 𝐵 )

Proof

Step Hyp Ref Expression
1 esumsnf.0 𝑘 𝐵
2 esumsnf.1 ( ( 𝜑𝑘 = 𝑀 ) → 𝐴 = 𝐵 )
3 esumsnf.2 ( 𝜑𝑀𝑉 )
4 esumsnf.3 ( 𝜑𝐵 ∈ ( 0 [,] +∞ ) )
5 df-esum Σ* 𝑘 ∈ { 𝑀 } 𝐴 = ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) tsums ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) )
6 5 a1i ( 𝜑 → Σ* 𝑘 ∈ { 𝑀 } 𝐴 = ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) tsums ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ) )
7 eqid ( ℝ*𝑠s ( 0 [,] +∞ ) ) = ( ℝ*𝑠s ( 0 [,] +∞ ) )
8 snfi { 𝑀 } ∈ Fin
9 8 a1i ( 𝜑 → { 𝑀 } ∈ Fin )
10 elsni ( 𝑘 ∈ { 𝑀 } → 𝑘 = 𝑀 )
11 10 2 sylan2 ( ( 𝜑𝑘 ∈ { 𝑀 } ) → 𝐴 = 𝐵 )
12 11 mpteq2dva ( 𝜑 → ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) = ( 𝑘 ∈ { 𝑀 } ↦ 𝐵 ) )
13 fmptsn ( ( 𝑀𝑉𝐵 ∈ ( 0 [,] +∞ ) ) → { ⟨ 𝑀 , 𝐵 ⟩ } = ( 𝑙 ∈ { 𝑀 } ↦ 𝐵 ) )
14 nfcv 𝑙 𝐵
15 eqidd ( 𝑘 = 𝑙𝐵 = 𝐵 )
16 14 1 15 cbvmpt ( 𝑘 ∈ { 𝑀 } ↦ 𝐵 ) = ( 𝑙 ∈ { 𝑀 } ↦ 𝐵 )
17 13 16 eqtr4di ( ( 𝑀𝑉𝐵 ∈ ( 0 [,] +∞ ) ) → { ⟨ 𝑀 , 𝐵 ⟩ } = ( 𝑘 ∈ { 𝑀 } ↦ 𝐵 ) )
18 3 4 17 syl2anc ( 𝜑 → { ⟨ 𝑀 , 𝐵 ⟩ } = ( 𝑘 ∈ { 𝑀 } ↦ 𝐵 ) )
19 12 18 eqtr4d ( 𝜑 → ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) = { ⟨ 𝑀 , 𝐵 ⟩ } )
20 fsng ( ( 𝑀𝑉𝐵 ∈ ( 0 [,] +∞ ) ) → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) : { 𝑀 } ⟶ { 𝐵 } ↔ ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) = { ⟨ 𝑀 , 𝐵 ⟩ } ) )
21 3 4 20 syl2anc ( 𝜑 → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) : { 𝑀 } ⟶ { 𝐵 } ↔ ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) = { ⟨ 𝑀 , 𝐵 ⟩ } ) )
22 19 21 mpbird ( 𝜑 → ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) : { 𝑀 } ⟶ { 𝐵 } )
23 4 snssd ( 𝜑 → { 𝐵 } ⊆ ( 0 [,] +∞ ) )
24 22 23 fssd ( 𝜑 → ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) : { 𝑀 } ⟶ ( 0 [,] +∞ ) )
25 xrltso < Or ℝ*
26 25 a1i ( 𝜑 → < Or ℝ* )
27 0xr 0 ∈ ℝ*
28 27 a1i ( 𝜑 → 0 ∈ ℝ* )
29 elxrge0 ( 𝐵 ∈ ( 0 [,] +∞ ) ↔ ( 𝐵 ∈ ℝ* ∧ 0 ≤ 𝐵 ) )
30 4 29 sylib ( 𝜑 → ( 𝐵 ∈ ℝ* ∧ 0 ≤ 𝐵 ) )
31 30 simpld ( 𝜑𝐵 ∈ ℝ* )
32 suppr ( ( < Or ℝ* ∧ 0 ∈ ℝ*𝐵 ∈ ℝ* ) → sup ( { 0 , 𝐵 } , ℝ* , < ) = if ( 𝐵 < 0 , 0 , 𝐵 ) )
33 26 28 31 32 syl3anc ( 𝜑 → sup ( { 0 , 𝐵 } , ℝ* , < ) = if ( 𝐵 < 0 , 0 , 𝐵 ) )
34 0fin ∅ ∈ Fin
35 34 a1i ( 𝜑 → ∅ ∈ Fin )
36 reseq2 ( 𝑥 = ∅ → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) = ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ ∅ ) )
37 res0 ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ ∅ ) = ∅
38 36 37 eqtrdi ( 𝑥 = ∅ → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) = ∅ )
39 38 oveq2d ( 𝑥 = ∅ → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ∅ ) )
40 xrge00 0 = ( 0g ‘ ( ℝ*𝑠s ( 0 [,] +∞ ) ) )
41 40 gsum0 ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ∅ ) = 0
42 39 41 eqtrdi ( 𝑥 = ∅ → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = 0 )
43 42 adantl ( ( 𝜑𝑥 = ∅ ) → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = 0 )
44 reseq2 ( 𝑥 = { 𝑀 } → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) = ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ { 𝑀 } ) )
45 ssid { 𝑀 } ⊆ { 𝑀 }
46 resmpt ( { 𝑀 } ⊆ { 𝑀 } → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ { 𝑀 } ) = ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) )
47 45 46 ax-mp ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ { 𝑀 } ) = ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 )
48 44 47 eqtrdi ( 𝑥 = { 𝑀 } → ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) = ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) )
49 48 oveq2d ( 𝑥 = { 𝑀 } → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ) )
50 xrge0base ( 0 [,] +∞ ) = ( Base ‘ ( ℝ*𝑠s ( 0 [,] +∞ ) ) )
51 xrge0cmn ( ℝ*𝑠s ( 0 [,] +∞ ) ) ∈ CMnd
52 cmnmnd ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) ∈ CMnd → ( ℝ*𝑠s ( 0 [,] +∞ ) ) ∈ Mnd )
53 51 52 ax-mp ( ℝ*𝑠s ( 0 [,] +∞ ) ) ∈ Mnd
54 53 a1i ( 𝜑 → ( ℝ*𝑠s ( 0 [,] +∞ ) ) ∈ Mnd )
55 nfv 𝑘 𝜑
56 50 54 3 4 2 55 1 gsumsnfd ( 𝜑 → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ) = 𝐵 )
57 49 56 sylan9eqr ( ( 𝜑𝑥 = { 𝑀 } ) → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = 𝐵 )
58 35 9 28 4 43 57 fmptpr ( 𝜑 → { ⟨ ∅ , 0 ⟩ , ⟨ { 𝑀 } , 𝐵 ⟩ } = ( 𝑥 ∈ { ∅ , { 𝑀 } } ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) )
59 pwsn 𝒫 { 𝑀 } = { ∅ , { 𝑀 } }
60 prssi ( ( ∅ ∈ Fin ∧ { 𝑀 } ∈ Fin ) → { ∅ , { 𝑀 } } ⊆ Fin )
61 34 8 60 mp2an { ∅ , { 𝑀 } } ⊆ Fin
62 59 61 eqsstri 𝒫 { 𝑀 } ⊆ Fin
63 df-ss ( 𝒫 { 𝑀 } ⊆ Fin ↔ ( 𝒫 { 𝑀 } ∩ Fin ) = 𝒫 { 𝑀 } )
64 62 63 mpbi ( 𝒫 { 𝑀 } ∩ Fin ) = 𝒫 { 𝑀 }
65 64 59 eqtri ( 𝒫 { 𝑀 } ∩ Fin ) = { ∅ , { 𝑀 } }
66 eqid ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) = ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) )
67 65 66 mpteq12i ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) = ( 𝑥 ∈ { ∅ , { 𝑀 } } ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) )
68 58 67 eqtr4di ( 𝜑 → { ⟨ ∅ , 0 ⟩ , ⟨ { 𝑀 } , 𝐵 ⟩ } = ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) )
69 68 rneqd ( 𝜑 → ran { ⟨ ∅ , 0 ⟩ , ⟨ { 𝑀 } , 𝐵 ⟩ } = ran ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) )
70 rnpropg ( ( ∅ ∈ Fin ∧ { 𝑀 } ∈ Fin ) → ran { ⟨ ∅ , 0 ⟩ , ⟨ { 𝑀 } , 𝐵 ⟩ } = { 0 , 𝐵 } )
71 35 9 70 syl2anc ( 𝜑 → ran { ⟨ ∅ , 0 ⟩ , ⟨ { 𝑀 } , 𝐵 ⟩ } = { 0 , 𝐵 } )
72 69 71 eqtr3d ( 𝜑 → ran ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) = { 0 , 𝐵 } )
73 72 supeq1d ( 𝜑 → sup ( ran ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) , ℝ* , < ) = sup ( { 0 , 𝐵 } , ℝ* , < ) )
74 30 simprd ( 𝜑 → 0 ≤ 𝐵 )
75 xrlenlt ( ( 0 ∈ ℝ*𝐵 ∈ ℝ* ) → ( 0 ≤ 𝐵 ↔ ¬ 𝐵 < 0 ) )
76 28 31 75 syl2anc ( 𝜑 → ( 0 ≤ 𝐵 ↔ ¬ 𝐵 < 0 ) )
77 74 76 mpbid ( 𝜑 → ¬ 𝐵 < 0 )
78 eqidd ( 𝜑𝐵 = 𝐵 )
79 77 78 jca ( 𝜑 → ( ¬ 𝐵 < 0 ∧ 𝐵 = 𝐵 ) )
80 79 olcd ( 𝜑 → ( ( 𝐵 < 0 ∧ 𝐵 = 0 ) ∨ ( ¬ 𝐵 < 0 ∧ 𝐵 = 𝐵 ) ) )
81 eqif ( 𝐵 = if ( 𝐵 < 0 , 0 , 𝐵 ) ↔ ( ( 𝐵 < 0 ∧ 𝐵 = 0 ) ∨ ( ¬ 𝐵 < 0 ∧ 𝐵 = 𝐵 ) ) )
82 80 81 sylibr ( 𝜑𝐵 = if ( 𝐵 < 0 , 0 , 𝐵 ) )
83 33 73 82 3eqtr4rd ( 𝜑𝐵 = sup ( ran ( 𝑥 ∈ ( 𝒫 { 𝑀 } ∩ Fin ) ↦ ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) Σg ( ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ↾ 𝑥 ) ) ) , ℝ* , < ) )
84 7 9 24 83 xrge0tsmsd ( 𝜑 → ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) tsums ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ) = { 𝐵 } )
85 84 unieqd ( 𝜑 ( ( ℝ*𝑠s ( 0 [,] +∞ ) ) tsums ( 𝑘 ∈ { 𝑀 } ↦ 𝐴 ) ) = { 𝐵 } )
86 unisng ( 𝐵 ∈ ( 0 [,] +∞ ) → { 𝐵 } = 𝐵 )
87 4 86 syl ( 𝜑 { 𝐵 } = 𝐵 )
88 6 85 87 3eqtrd ( 𝜑 → Σ* 𝑘 ∈ { 𝑀 } 𝐴 = 𝐵 )