Metamath Proof Explorer


Theorem regsumsupp

Description: The group sum over the real numbers, expressed as a finite sum. (Contributed by Thierry Arnoux, 22-Jun-2019) (Proof shortened by AV, 19-Jul-2019)

Ref Expression
Assertion regsumsupp F : I finSupp 0 F I V fld F = x F supp 0 F x

Proof

Step Hyp Ref Expression
1 cnfldbas = Base fld
2 cnfld0 0 = 0 fld
3 cnring fld Ring
4 ringcmn fld Ring fld CMnd
5 3 4 mp1i F : I finSupp 0 F I V fld CMnd
6 simp3 F : I finSupp 0 F I V I V
7 simp1 F : I finSupp 0 F I V F : I
8 ax-resscn
9 fss F : I F : I
10 7 8 9 sylancl F : I finSupp 0 F I V F : I
11 ssidd F : I finSupp 0 F I V F supp 0 F supp 0
12 simp2 F : I finSupp 0 F I V finSupp 0 F
13 1 2 5 6 10 11 12 gsumres F : I finSupp 0 F I V fld F supp 0 F = fld F
14 cnfldadd + = + fld
15 df-refld fld = fld 𝑠
16 8 a1i F : I finSupp 0 F I V
17 0red F : I finSupp 0 F I V 0
18 simpr F : I finSupp 0 F I V x x
19 18 addid2d F : I finSupp 0 F I V x 0 + x = x
20 18 addid1d F : I finSupp 0 F I V x x + 0 = x
21 19 20 jca F : I finSupp 0 F I V x 0 + x = x x + 0 = x
22 1 14 15 5 6 16 7 17 21 gsumress F : I finSupp 0 F I V fld F = fld F
23 13 22 eqtr2d F : I finSupp 0 F I V fld F = fld F supp 0 F
24 suppssdm F supp 0 dom F
25 24 7 fssdm F : I finSupp 0 F I V F supp 0 I
26 7 25 feqresmpt F : I finSupp 0 F I V F supp 0 F = x supp 0 F F x
27 26 oveq2d F : I finSupp 0 F I V fld F supp 0 F = fld x F supp 0 F x
28 12 fsuppimpd F : I finSupp 0 F I V F supp 0 Fin
29 simpl1 F : I finSupp 0 F I V x supp 0 F F : I
30 25 sselda F : I finSupp 0 F I V x supp 0 F x I
31 29 30 ffvelrnd F : I finSupp 0 F I V x supp 0 F F x
32 8 31 sseldi F : I finSupp 0 F I V x supp 0 F F x
33 28 32 gsumfsum F : I finSupp 0 F I V fld x F supp 0 F x = x F supp 0 F x
34 23 27 33 3eqtrd F : I finSupp 0 F I V fld F = x F supp 0 F x