Metamath Proof Explorer


Theorem gsumval2a

Description: Value of the group sum operation over a finite set of sequential integers. (Contributed by Mario Carneiro, 7-Dec-2014)

Ref Expression
Hypotheses gsumval2.b B = Base G
gsumval2.p + ˙ = + G
gsumval2.g φ G V
gsumval2.n φ N M
gsumval2.f φ F : M N B
gsumval2a.o O = x B | y B x + ˙ y = y y + ˙ x = y
gsumval2a.f φ ¬ ran F O
Assertion gsumval2a φ G F = seq M + ˙ F N

Proof

Step Hyp Ref Expression
1 gsumval2.b B = Base G
2 gsumval2.p + ˙ = + G
3 gsumval2.g φ G V
4 gsumval2.n φ N M
5 gsumval2.f φ F : M N B
6 gsumval2a.o O = x B | y B x + ˙ y = y y + ˙ x = y
7 gsumval2a.f φ ¬ ran F O
8 eqid 0 G = 0 G
9 eqidd φ F -1 V O = F -1 V O
10 ovexd φ M N V
11 1 8 2 6 9 3 10 5 gsumval φ G F = if ran F O 0 G if M N ran ι z | m n m M N = m n z = seq m + ˙ F n ι z | f f : 1 F -1 V O 1-1 onto F -1 V O z = seq 1 + ˙ F f F -1 V O
12 7 iffalsed φ if ran F O 0 G if M N ran ι z | m n m M N = m n z = seq m + ˙ F n ι z | f f : 1 F -1 V O 1-1 onto F -1 V O z = seq 1 + ˙ F f F -1 V O = if M N ran ι z | m n m M N = m n z = seq m + ˙ F n ι z | f f : 1 F -1 V O 1-1 onto F -1 V O z = seq 1 + ˙ F f F -1 V O
13 fzf : × 𝒫
14 ffn : × 𝒫 Fn ×
15 13 14 ax-mp Fn ×
16 eluzel2 N M M
17 4 16 syl φ M
18 eluzelz N M N
19 4 18 syl φ N
20 fnovrn Fn × M N M N ran
21 15 17 19 20 mp3an2i φ M N ran
22 21 iftrued φ if M N ran ι z | m n m M N = m n z = seq m + ˙ F n ι z | f f : 1 F -1 V O 1-1 onto F -1 V O z = seq 1 + ˙ F f F -1 V O = ι z | m n m M N = m n z = seq m + ˙ F n
23 12 22 eqtrd φ if ran F O 0 G if M N ran ι z | m n m M N = m n z = seq m + ˙ F n ι z | f f : 1 F -1 V O 1-1 onto F -1 V O z = seq 1 + ˙ F f F -1 V O = ι z | m n m M N = m n z = seq m + ˙ F n
24 11 23 eqtrd φ G F = ι z | m n m M N = m n z = seq m + ˙ F n
25 fvex seq M + ˙ F N V
26 fzopth N M M N = m n M = m N = n
27 4 26 syl φ M N = m n M = m N = n
28 simpl M = m N = n M = m
29 28 seqeq1d M = m N = n seq M + ˙ F = seq m + ˙ F
30 simpr M = m N = n N = n
31 29 30 fveq12d M = m N = n seq M + ˙ F N = seq m + ˙ F n
32 31 eqcomd M = m N = n seq m + ˙ F n = seq M + ˙ F N
33 eqeq1 z = seq m + ˙ F n z = seq M + ˙ F N seq m + ˙ F n = seq M + ˙ F N
34 32 33 syl5ibrcom M = m N = n z = seq m + ˙ F n z = seq M + ˙ F N
35 27 34 syl6bi φ M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
36 35 impd φ M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
37 36 rexlimdvw φ n m M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
38 37 exlimdv φ m n m M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
39 17 adantr φ z = seq M + ˙ F N M
40 oveq2 n = N M n = M N
41 40 eqcomd n = N M N = M n
42 41 biantrurd n = N z = seq M + ˙ F n M N = M n z = seq M + ˙ F n
43 fveq2 n = N seq M + ˙ F n = seq M + ˙ F N
44 43 eqeq2d n = N z = seq M + ˙ F n z = seq M + ˙ F N
45 42 44 bitr3d n = N M N = M n z = seq M + ˙ F n z = seq M + ˙ F N
46 45 rspcev N M z = seq M + ˙ F N n M M N = M n z = seq M + ˙ F n
47 4 46 sylan φ z = seq M + ˙ F N n M M N = M n z = seq M + ˙ F n
48 fveq2 m = M m = M
49 oveq1 m = M m n = M n
50 49 eqeq2d m = M M N = m n M N = M n
51 seqeq1 m = M seq m + ˙ F = seq M + ˙ F
52 51 fveq1d m = M seq m + ˙ F n = seq M + ˙ F n
53 52 eqeq2d m = M z = seq m + ˙ F n z = seq M + ˙ F n
54 50 53 anbi12d m = M M N = m n z = seq m + ˙ F n M N = M n z = seq M + ˙ F n
55 48 54 rexeqbidv m = M n m M N = m n z = seq m + ˙ F n n M M N = M n z = seq M + ˙ F n
56 55 spcegv M n M M N = M n z = seq M + ˙ F n m n m M N = m n z = seq m + ˙ F n
57 39 47 56 sylc φ z = seq M + ˙ F N m n m M N = m n z = seq m + ˙ F n
58 57 ex φ z = seq M + ˙ F N m n m M N = m n z = seq m + ˙ F n
59 38 58 impbid φ m n m M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
60 59 adantr φ seq M + ˙ F N V m n m M N = m n z = seq m + ˙ F n z = seq M + ˙ F N
61 60 iota5 φ seq M + ˙ F N V ι z | m n m M N = m n z = seq m + ˙ F n = seq M + ˙ F N
62 25 61 mpan2 φ ι z | m n m M N = m n z = seq m + ˙ F n = seq M + ˙ F N
63 24 62 eqtrd φ G F = seq M + ˙ F N