Theorem gfsump1 16885

Description: Splitting off one element from a finite group sum. This would typically used in a proof by induction. (Contributed by Jim Kingdon, 3-Apr-2026.)

Hypotheses

Ref	Expression
gfsump1.b	⊢ 𝐵 = (Base‘𝐺)
gfsump1.p	⊢ + = (+g‘𝐺)
gfsump1.g	⊢ (𝜑 → 𝐺 ∈ CMnd)
gfsump1.f	⊢ (𝜑 → 𝐹:(𝑌 ∪ {𝑍})⟶𝐵)
gfsump1.fi	⊢ (𝜑 → 𝑌 ∈ Fin)
gfsump1.zv	⊢ (𝜑 → 𝑍 ∈ 𝑉)
gfsump1.z	⊢ (𝜑 → ¬ 𝑍 ∈ 𝑌)

Assertion

Ref	Expression
gfsump1	⊢ (𝜑 → (𝐺 Σgf 𝐹) = ((𝐺 Σgf (𝐹 ↾ 𝑌)) + (𝐹‘𝑍)))

Proof of Theorem gfsump1

Dummy variable ℎ is distinct from all other variables.

Step	Hyp	Ref	Expression
1		gfsump1.fi	. . 3 ⊢ (𝜑 → 𝑌 ∈ Fin)
2		fzf1o 12065	. . 3 ⊢ (𝑌 ∈ Fin → ∃ℎ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌)
3	1, 2	syl 14	. 2 ⊢ (𝜑 → ∃ℎ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌)
4		gfsump1.b	. . . . 5 ⊢ 𝐵 = (Base‘𝐺)
5		gfsump1.g	. . . . . 6 ⊢ (𝜑 → 𝐺 ∈ CMnd)
6	5	adantr 276	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 𝐺 ∈ CMnd)
7		gfsump1.f	. . . . . 6 ⊢ (𝜑 → 𝐹:(𝑌 ∪ {𝑍})⟶𝐵)
8	7	adantr 276	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 𝐹:(𝑌 ∪ {𝑍})⟶𝐵)
9		gfsump1.zv	. . . . . . 7 ⊢ (𝜑 → 𝑍 ∈ 𝑉)
10		gfsump1.z	. . . . . . 7 ⊢ (𝜑 → ¬ 𝑍 ∈ 𝑌)
11		unsnfi 7181	. . . . . . 7 ⊢ ((𝑌 ∈ Fin ∧ 𝑍 ∈ 𝑉 ∧ ¬ 𝑍 ∈ 𝑌) → (𝑌 ∪ {𝑍}) ∈ Fin)
12	1, 9, 10, 11	syl3anc 1274	. . . . . 6 ⊢ (𝜑 → (𝑌 ∪ {𝑍}) ∈ Fin)
13	12	adantr 276	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝑌 ∪ {𝑍}) ∈ Fin)
14		simpr 110	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌)
15		hashcl 11148	. . . . . . . . . . 11 ⊢ (𝑌 ∈ Fin → (♯‘𝑌) ∈ ℕ0)
16	1, 15	syl 14	. . . . . . . . . 10 ⊢ (𝜑 → (♯‘𝑌) ∈ ℕ0)
17		peano2nn0 9538	. . . . . . . . . 10 ⊢ ((♯‘𝑌) ∈ ℕ0 → ((♯‘𝑌) + 1) ∈ ℕ0)
18	16, 17	syl 14	. . . . . . . . 9 ⊢ (𝜑 → ((♯‘𝑌) + 1) ∈ ℕ0)
19		f1osng 5659	. . . . . . . . 9 ⊢ ((((♯‘𝑌) + 1) ∈ ℕ0 ∧ 𝑍 ∈ 𝑉) → {⟨((♯‘𝑌) + 1), 𝑍⟩}:{((♯‘𝑌) + 1)}–1-1-onto→{𝑍})
20	18, 9, 19	syl2anc 411	. . . . . . . 8 ⊢ (𝜑 → {⟨((♯‘𝑌) + 1), 𝑍⟩}:{((♯‘𝑌) + 1)}–1-1-onto→{𝑍})
21	20	adantr 276	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → {⟨((♯‘𝑌) + 1), 𝑍⟩}:{((♯‘𝑌) + 1)}–1-1-onto→{𝑍})
22		fzp1disj 10418	. . . . . . . 8 ⊢ ((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)}) = ∅
23	22	a1i 9	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)}) = ∅)
24		disjsn 3753	. . . . . . . . 9 ⊢ ((𝑌 ∩ {𝑍}) = ∅ ↔ ¬ 𝑍 ∈ 𝑌)
25	10, 24	sylibr 134	. . . . . . . 8 ⊢ (𝜑 → (𝑌 ∩ {𝑍}) = ∅)
26	25	adantr 276	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝑌 ∩ {𝑍}) = ∅)
27		f1oun 5636	. . . . . . 7 ⊢ (((ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌 ∧ {⟨((♯‘𝑌) + 1), 𝑍⟩}:{((♯‘𝑌) + 1)}–1-1-onto→{𝑍}) ∧ (((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)}) = ∅ ∧ (𝑌 ∩ {𝑍}) = ∅)) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)})–1-1-onto→(𝑌 ∪ {𝑍}))
28	14, 21, 23, 26, 27	syl22anc 1275	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)})–1-1-onto→(𝑌 ∪ {𝑍}))
29	1, 10	jca 306	. . . . . . . . . . 11 ⊢ (𝜑 → (𝑌 ∈ Fin ∧ ¬ 𝑍 ∈ 𝑌))
30		hashunsng 11176	. . . . . . . . . . 11 ⊢ (𝑍 ∈ 𝑉 → ((𝑌 ∈ Fin ∧ ¬ 𝑍 ∈ 𝑌) → (♯‘(𝑌 ∪ {𝑍})) = ((♯‘𝑌) + 1)))
31	9, 29, 30	sylc 62	. . . . . . . . . 10 ⊢ (𝜑 → (♯‘(𝑌 ∪ {𝑍})) = ((♯‘𝑌) + 1))
32	31	oveq2d 6068	. . . . . . . . 9 ⊢ (𝜑 → (1...(♯‘(𝑌 ∪ {𝑍}))) = (1...((♯‘𝑌) + 1)))
33		1z 9605	. . . . . . . . . 10 ⊢ 1 ∈ ℤ
34		nn0uz 9892	. . . . . . . . . . . 12 ⊢ ℕ0 = (ℤ≥‘0)
35		1m1e0 9308	. . . . . . . . . . . . 13 ⊢ (1 − 1) = 0
36	35	fveq2i 5675	. . . . . . . . . . . 12 ⊢ (ℤ≥‘(1 − 1)) = (ℤ≥‘0)
37	34, 36	eqtr4i 2258	. . . . . . . . . . 11 ⊢ ℕ0 = (ℤ≥‘(1 − 1))
38	16, 37	eleqtrdi 2327	. . . . . . . . . 10 ⊢ (𝜑 → (♯‘𝑌) ∈ (ℤ≥‘(1 − 1)))
39		fzsuc2 10417	. . . . . . . . . 10 ⊢ ((1 ∈ ℤ ∧ (♯‘𝑌) ∈ (ℤ≥‘(1 − 1))) → (1...((♯‘𝑌) + 1)) = ((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)}))
40	33, 38, 39	sylancr 414	. . . . . . . . 9 ⊢ (𝜑 → (1...((♯‘𝑌) + 1)) = ((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)}))
41	32, 40	eqtrd 2267	. . . . . . . 8 ⊢ (𝜑 → (1...(♯‘(𝑌 ∪ {𝑍}))) = ((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)}))
42	41	adantr 276	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (1...(♯‘(𝑌 ∪ {𝑍}))) = ((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)}))
43	42	f1oeq2d 5612	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...(♯‘(𝑌 ∪ {𝑍})))–1-1-onto→(𝑌 ∪ {𝑍}) ↔ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)})–1-1-onto→(𝑌 ∪ {𝑍})))
44	28, 43	mpbird 167	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...(♯‘(𝑌 ∪ {𝑍})))–1-1-onto→(𝑌 ∪ {𝑍}))
45	4, 6, 8, 13, 44	gfsumval 16879	. . . 4 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σgf 𝐹) = (𝐺 Σg (𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))))
46		gfsump1.p	. . . . 5 ⊢ + = (+g‘𝐺)
47	5	cmnmndd 14042	. . . . . 6 ⊢ (𝜑 → 𝐺 ∈ Mnd)
48	47	adantr 276	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 𝐺 ∈ Mnd)
49		1zzd 9606	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 1 ∈ ℤ)
50	38	adantr 276	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (♯‘𝑌) ∈ (ℤ≥‘(1 − 1)))
51	40	adantr 276	. . . . . . . . 9 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (1...((♯‘𝑌) + 1)) = ((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)}))
52	51	f1oeq2d 5612	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))–1-1-onto→(𝑌 ∪ {𝑍}) ↔ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):((1...(♯‘𝑌)) ∪ {((♯‘𝑌) + 1)})–1-1-onto→(𝑌 ∪ {𝑍})))
53	28, 52	mpbird 167	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))–1-1-onto→(𝑌 ∪ {𝑍}))
54		f1of 5616	. . . . . . 7 ⊢ ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))–1-1-onto→(𝑌 ∪ {𝑍}) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))⟶(𝑌 ∪ {𝑍}))
55	53, 54	syl 14	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))⟶(𝑌 ∪ {𝑍}))
56		fco 5529	. . . . . 6 ⊢ ((𝐹:(𝑌 ∪ {𝑍})⟶𝐵 ∧ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))⟶(𝑌 ∪ {𝑍})) → (𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})):(1...((♯‘𝑌) + 1))⟶𝐵)
57	8, 55, 56	syl2anc 411	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})):(1...((♯‘𝑌) + 1))⟶𝐵)
58	4, 46, 48, 49, 50, 57	gsumsplit0 14080	. . . 4 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σg (𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))) = ((𝐺 Σg ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌)))) + ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1))))
59	45, 58	eqtrd 2267	. . 3 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σgf 𝐹) = ((𝐺 Σg ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌)))) + ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1))))
60		resco 5269	. . . . . . . . . 10 ⊢ ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌))) = (𝐹 ∘ ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}) ↾ (1...(♯‘𝑌))))
61		resundir 5054	. . . . . . . . . . . 12 ⊢ ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}) ↾ (1...(♯‘𝑌))) = ((ℎ ↾ (1...(♯‘𝑌))) ∪ ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌))))
62		incom 3413	. . . . . . . . . . . . . . . 16 ⊢ ({((♯‘𝑌) + 1)} ∩ (1...(♯‘𝑌))) = ((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)})
63	62, 22	eqtri 2255	. . . . . . . . . . . . . . 15 ⊢ ({((♯‘𝑌) + 1)} ∩ (1...(♯‘𝑌))) = ∅
64		fnsng 5405	. . . . . . . . . . . . . . . . 17 ⊢ ((((♯‘𝑌) + 1) ∈ ℕ0 ∧ 𝑍 ∈ 𝑉) → {⟨((♯‘𝑌) + 1), 𝑍⟩} Fn {((♯‘𝑌) + 1)})
65	18, 9, 64	syl2anc 411	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → {⟨((♯‘𝑌) + 1), 𝑍⟩} Fn {((♯‘𝑌) + 1)})
66		fnresdisj 5470	. . . . . . . . . . . . . . . 16 ⊢ ({⟨((♯‘𝑌) + 1), 𝑍⟩} Fn {((♯‘𝑌) + 1)} → (({((♯‘𝑌) + 1)} ∩ (1...(♯‘𝑌))) = ∅ ↔ ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌))) = ∅))
67	65, 66	syl 14	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → (({((♯‘𝑌) + 1)} ∩ (1...(♯‘𝑌))) = ∅ ↔ ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌))) = ∅))
68	63, 67	mpbii 148	. . . . . . . . . . . . . 14 ⊢ (𝜑 → ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌))) = ∅)
69	68	uneq2d 3375	. . . . . . . . . . . . 13 ⊢ (𝜑 → ((ℎ ↾ (1...(♯‘𝑌))) ∪ ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌)))) = ((ℎ ↾ (1...(♯‘𝑌))) ∪ ∅))
70		un0 3544	. . . . . . . . . . . . 13 ⊢ ((ℎ ↾ (1...(♯‘𝑌))) ∪ ∅) = (ℎ ↾ (1...(♯‘𝑌)))
71	69, 70	eqtrdi 2283	. . . . . . . . . . . 12 ⊢ (𝜑 → ((ℎ ↾ (1...(♯‘𝑌))) ∪ ({⟨((♯‘𝑌) + 1), 𝑍⟩} ↾ (1...(♯‘𝑌)))) = (ℎ ↾ (1...(♯‘𝑌))))
72	61, 71	eqtrid 2279	. . . . . . . . . . 11 ⊢ (𝜑 → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}) ↾ (1...(♯‘𝑌))) = (ℎ ↾ (1...(♯‘𝑌))))
73	72	coeq2d 4919	. . . . . . . . . 10 ⊢ (𝜑 → (𝐹 ∘ ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}) ↾ (1...(♯‘𝑌)))) = (𝐹 ∘ (ℎ ↾ (1...(♯‘𝑌)))))
74	60, 73	eqtrid 2279	. . . . . . . . 9 ⊢ (𝜑 → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌))) = (𝐹 ∘ (ℎ ↾ (1...(♯‘𝑌)))))
75	74	adantr 276	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌))) = (𝐹 ∘ (ℎ ↾ (1...(♯‘𝑌)))))
76		f1ofn 5617	. . . . . . . . . . 11 ⊢ (ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌 → ℎ Fn (1...(♯‘𝑌)))
77		fnresdm 5469	. . . . . . . . . . 11 ⊢ (ℎ Fn (1...(♯‘𝑌)) → (ℎ ↾ (1...(♯‘𝑌))) = ℎ)
78	76, 77	syl 14	. . . . . . . . . 10 ⊢ (ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌 → (ℎ ↾ (1...(♯‘𝑌))) = ℎ)
79	78	adantl 277	. . . . . . . . 9 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (ℎ ↾ (1...(♯‘𝑌))) = ℎ)
80	79	coeq2d 4919	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐹 ∘ (ℎ ↾ (1...(♯‘𝑌)))) = (𝐹 ∘ ℎ))
81	75, 80	eqtrd 2267	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌))) = (𝐹 ∘ ℎ))
82		f1of 5616	. . . . . . . . . 10 ⊢ (ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌 → ℎ:(1...(♯‘𝑌))⟶𝑌)
83	82	adantl 277	. . . . . . . . 9 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ℎ:(1...(♯‘𝑌))⟶𝑌)
84	83	frnd 5520	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ran ℎ ⊆ 𝑌)
85		cores 5268	. . . . . . . 8 ⊢ (ran ℎ ⊆ 𝑌 → ((𝐹 ↾ 𝑌) ∘ ℎ) = (𝐹 ∘ ℎ))
86	84, 85	syl 14	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ↾ 𝑌) ∘ ℎ) = (𝐹 ∘ ℎ))
87	81, 86	eqtr4d 2270	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌))) = ((𝐹 ↾ 𝑌) ∘ ℎ))
88	87	oveq2d 6068	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σg ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌)))) = (𝐺 Σg ((𝐹 ↾ 𝑌) ∘ ℎ)))
89		ssun1 3384	. . . . . . . . 9 ⊢ 𝑌 ⊆ (𝑌 ∪ {𝑍})
90	89	a1i 9	. . . . . . . 8 ⊢ (𝜑 → 𝑌 ⊆ (𝑌 ∪ {𝑍}))
91	7, 90	fssresd 5543	. . . . . . 7 ⊢ (𝜑 → (𝐹 ↾ 𝑌):𝑌⟶𝐵)
92	91	adantr 276	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐹 ↾ 𝑌):𝑌⟶𝐵)
93	1	adantr 276	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 𝑌 ∈ Fin)
94	4, 6, 92, 93, 14	gfsumval 16879	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σgf (𝐹 ↾ 𝑌)) = (𝐺 Σg ((𝐹 ↾ 𝑌) ∘ ℎ)))
95	88, 94	eqtr4d 2270	. . . 4 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σg ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌)))) = (𝐺 Σgf (𝐹 ↾ 𝑌)))
96		nn0p1nn 9537	. . . . . . . . . 10 ⊢ ((♯‘𝑌) ∈ ℕ0 → ((♯‘𝑌) + 1) ∈ ℕ)
97	16, 96	syl 14	. . . . . . . . 9 ⊢ (𝜑 → ((♯‘𝑌) + 1) ∈ ℕ)
98		nnuz 9893	. . . . . . . . 9 ⊢ ℕ = (ℤ≥‘1)
99	97, 98	eleqtrdi 2327	. . . . . . . 8 ⊢ (𝜑 → ((♯‘𝑌) + 1) ∈ (ℤ≥‘1))
100		eluzfz2 10369	. . . . . . . 8 ⊢ (((♯‘𝑌) + 1) ∈ (ℤ≥‘1) → ((♯‘𝑌) + 1) ∈ (1...((♯‘𝑌) + 1)))
101	99, 100	syl 14	. . . . . . 7 ⊢ (𝜑 → ((♯‘𝑌) + 1) ∈ (1...((♯‘𝑌) + 1)))
102	101	adantr 276	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((♯‘𝑌) + 1) ∈ (1...((♯‘𝑌) + 1)))
103		fvco3 5750	. . . . . 6 ⊢ (((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}):(1...((♯‘𝑌) + 1))⟶(𝑌 ∪ {𝑍}) ∧ ((♯‘𝑌) + 1) ∈ (1...((♯‘𝑌) + 1))) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1)) = (𝐹‘((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1))))
104	55, 102, 103	syl2anc 411	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1)) = (𝐹‘((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1))))
105	76	adantl 277	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ℎ Fn (1...(♯‘𝑌)))
106	65	adantr 276	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → {⟨((♯‘𝑌) + 1), 𝑍⟩} Fn {((♯‘𝑌) + 1)})
107	18	adantr 276	. . . . . . . . . 10 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((♯‘𝑌) + 1) ∈ ℕ0)
108		snidg 3720	. . . . . . . . . 10 ⊢ (((♯‘𝑌) + 1) ∈ ℕ0 → ((♯‘𝑌) + 1) ∈ {((♯‘𝑌) + 1)})
109	107, 108	syl 14	. . . . . . . . 9 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((♯‘𝑌) + 1) ∈ {((♯‘𝑌) + 1)})
110	23, 109	jca 306	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)}) = ∅ ∧ ((♯‘𝑌) + 1) ∈ {((♯‘𝑌) + 1)}))
111		fvun2 5746	. . . . . . . 8 ⊢ ((ℎ Fn (1...(♯‘𝑌)) ∧ {⟨((♯‘𝑌) + 1), 𝑍⟩} Fn {((♯‘𝑌) + 1)} ∧ (((1...(♯‘𝑌)) ∩ {((♯‘𝑌) + 1)}) = ∅ ∧ ((♯‘𝑌) + 1) ∈ {((♯‘𝑌) + 1)})) → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1)) = ({⟨((♯‘𝑌) + 1), 𝑍⟩}‘((♯‘𝑌) + 1)))
112	105, 106, 110, 111	syl3anc 1274	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1)) = ({⟨((♯‘𝑌) + 1), 𝑍⟩}‘((♯‘𝑌) + 1)))
113	9	adantr 276	. . . . . . . 8 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → 𝑍 ∈ 𝑉)
114		fvsng 5882	. . . . . . . 8 ⊢ ((((♯‘𝑌) + 1) ∈ ℕ0 ∧ 𝑍 ∈ 𝑉) → ({⟨((♯‘𝑌) + 1), 𝑍⟩}‘((♯‘𝑌) + 1)) = 𝑍)
115	107, 113, 114	syl2anc 411	. . . . . . 7 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ({⟨((♯‘𝑌) + 1), 𝑍⟩}‘((♯‘𝑌) + 1)) = 𝑍)
116	112, 115	eqtrd 2267	. . . . . 6 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1)) = 𝑍)
117	116	fveq2d 5676	. . . . 5 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐹‘((ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})‘((♯‘𝑌) + 1))) = (𝐹‘𝑍))
118	104, 117	eqtrd 2267	. . . 4 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1)) = (𝐹‘𝑍))
119	95, 118	oveq12d 6070	. . 3 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → ((𝐺 Σg ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩})) ↾ (1...(♯‘𝑌)))) + ((𝐹 ∘ (ℎ ∪ {⟨((♯‘𝑌) + 1), 𝑍⟩}))‘((♯‘𝑌) + 1))) = ((𝐺 Σgf (𝐹 ↾ 𝑌)) + (𝐹‘𝑍)))
120	59, 119	eqtrd 2267	. 2 ⊢ ((𝜑 ∧ ℎ:(1...(♯‘𝑌))–1-1-onto→𝑌) → (𝐺 Σgf 𝐹) = ((𝐺 Σgf (𝐹 ↾ 𝑌)) + (𝐹‘𝑍)))
121	3, 120	exlimddv 1950	1 ⊢ (𝜑 → (𝐺 Σgf 𝐹) = ((𝐺 Σgf (𝐹 ↾ 𝑌)) + (𝐹‘𝑍)))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 104   ↔ wb 105   = wceq 1398  ∃wex 1541   ∈ wcel 2205   ∪ cun 3211   ∩ cin 3212   ⊆ wss 3213  ∅c0 3510  {csn 3691  ⟨cop 3694  ran crn 4752   ↾ cres 4753   ∘ ccom 4755   Fn wfn 5349  ⟶wf 5350  –1-1-onto→wf1o 5353  ‘cfv 5354  (class class class)co 6052  Fincfn 6977  0cc0 8129  1c1 8130   + caddc 8132   − cmin 8446  ℕcn 9239  ℕ₀cn0 9498  ℤcz 9579  ℤ_≥cuz 9856  ...cfz 10345  ♯chash 11142  Basecbs 13229  +_gcplusg 13307   Σ_g cgsu 13487  Mndcmnd 13646  CMndccmn 14018   Σ_gf cgfsu 16877

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2207  ax-14 2208  ax-ext 2216  ax-coll 4227  ax-sep 4230  ax-nul 4238  ax-pow 4289  ax-pr 4324  ax-un 4556  ax-setind 4661  ax-iinf 4712  ax-cnex 8220  ax-resscn 8221  ax-1cn 8222  ax-1re 8223  ax-icn 8224  ax-addcl 8225  ax-addrcl 8226  ax-mulcl 8227  ax-mulrcl 8228  ax-addcom 8229  ax-mulcom 8230  ax-addass 8231  ax-mulass 8232  ax-distr 8233  ax-i2m1 8234  ax-0lt1 8235  ax-1rid 8236  ax-0id 8237  ax-rnegex 8238  ax-precex 8239  ax-cnre 8240  ax-pre-ltirr 8241  ax-pre-ltwlin 8242  ax-pre-lttrn 8243  ax-pre-apti 8244  ax-pre-ltadd 8245  ax-pre-mulgt0 8246

This theorem depends on definitions:  df-bi 117  df-stab 839  df-dc 843  df-3or 1006  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ne 2415  df-nel 2510  df-ral 2527  df-rex 2528  df-reu 2529  df-rmo 2530  df-rab 2531  df-v 2817  df-sbc 3045  df-csb 3141  df-dif 3215  df-un 3217  df-in 3219  df-ss 3226  df-nul 3511  df-if 3623  df-pw 3673  df-sn 3697  df-pr 3698  df-op 3700  df-uni 3917  df-int 3952  df-iun 3995  df-br 4112  df-opab 4174  df-mpt 4175  df-tr 4211  df-id 4416  df-iord 4489  df-on 4491  df-ilim 4492  df-suc 4494  df-iom 4715  df-xp 4757  df-rel 4758  df-cnv 4759  df-co 4760  df-dm 4761  df-rn 4762  df-res 4763  df-ima 4764  df-iota 5314  df-fun 5356  df-fn 5357  df-f 5358  df-f1 5359  df-fo 5360  df-f1o 5361  df-fv 5362  df-riota 6005  df-ov 6055  df-oprab 6056  df-mpo 6057  df-1st 6336  df-2nd 6337  df-recs 6538  df-irdg 6603  df-frec 6624  df-1o 6649  df-oadd 6653  df-er 6769  df-en 6978  df-dom 6979  df-fin 6980  df-pnf 8312  df-mnf 8313  df-xr 8314  df-ltxr 8315  df-le 8316  df-sub 8448  df-neg 8449  df-reap 8851  df-ap 8858  df-inn 9240  df-2 9298  df-n0 9499  df-z 9580  df-uz 9857  df-fz 10346  df-fzo 10481  df-seqfrec 10814  df-ihash 11143  df-ndx 13232  df-slot 13233  df-base 13235  df-plusg 13320  df-0g 13488  df-igsum 13489  df-mgm 13586  df-sgrp 13632  df-mnd 13647  df-minusg 13734  df-mulg 13854  df-cmn 14020  df-gfsum 16878

This theorem is referenced by:  gfsumz  16886  gfsumcl  16887